completed missing data for the Google sheets citation tutorial

book/manipulations/gsheets_citations.md

@@ -18,13 +18,11 @@
 ```
 
 ## Summary
-In many research contexts access to the literature is very important and dealing with its metadata can be time-consuming.
+In many research contexts, access to the literature is very important and dealing with its metadata can be time-consuming.
 The advent of the [Digital Object Identifier](https://www.doi.org/) (DOI) has made it much easier to deal with 
-citation data for many different types of digital resources.  Currently, twelve 
-[registration agencies](https://www.doi.org/the-community/existing-registration-agencies/) are 'minting' (creating) 
-DOI's and each has a different scope and size.  From a research literature perspective 
-[CrossRef](https://www.crossref.org/) is the agency that holds DOI's (now  
-[~150,000,000](https://www.crossref.org/06members/53status.html)) and that is a lot of data to sort through.
+citation data for many different types of digital resources.  Currently, twelve [registration agencies](https://www.doi.org/the-community/existing-registration-agencies/) are 
+'minting' (creating) DOI's and each has a different scope and size.  From a research literature perspective 
+[CrossRef](https://www.crossref.org/) is the agency  that holds DOI's (now [~150,000,000](https://www.crossref.org/06members/53status.html)) and that is a lot of data to sort through.
 
 This tutorial therefore focuses on understanding how you can pull in citation metadata from the CrossRef API, and 
 load it in a Google Sheet, to make it easy (for instance) to create a citation string for a paper.  An example of a
@@ -33,20 +31,76 @@ and you can make a copy and play around with it. Exploring what it takes to put
 way to understand the CrossRef schema, the structure of how the data is provided.
 
 ## 1 Accessing the CrossRef API
-The CrossRef API makes available metadata about journal papers, books and other publication types.  Detailed documentation
+The CrossRef API makes metadata available about journal papers, books and other publication types.  Detailed documentation
 of the API is available at main URL endpoint, https://api.crossref.org.  This is too big to go over in this tutorial, so
 we will just be focusing on the 'works' endpoint (a partial URL that you can add a DOI to) - in this case
-https://api.crossref.org/works/.  If you append a DOI to the end of this partial URL and put it in a browser you will 
-get a JSON file returned (see below).  The JSON file is formatted using the [JSONView](https://jsonview.com/) 
+https://api.crossref.org/works/.  If you append a DOI to this partial URL and put it in a browser you will 
+get a JSON file returned (see below).  The JSON file in the image is formatted using the [JSONView](https://jsonview.com/) 
 plugin for Firefox and all the fields have been collapsed to make it easy to see the whole file at
 http://api.crossref.org/works/10.1515/pac-2018-1010.
 
 ![fig](../images/gsheets_citations_crossref_api.jpg)
-
 Caption: JSON output from the Crossref API
 
-The data we need to extra to be able to criteria a citation for this paper is spread throughoout different parts of the
-JSON file, so we need to know how to get to these metadata. You can think about accessing information in the JSON file
-by using the concept of 'paths' to the data elements. This is the same as the path to a file on your computer, going
-down into subdirectories until you reach the file. In this case data we need are at the following paths and
+The data we need to extract to be able to create a citation for this paper is spread throughoout different parts of the
+JSON file, so we need to know how to get to these metadata elements. You can think about accessing information in the 
+JSON file by using the concept of 'paths' to the data elements (just like accessing files in a computer). In this case 
+the data we need are at the following paths:
+
+- **title**: /message/title
+- **author last names**: /message/author/given (for each author)
+- **author first names**: /message/author/family (for each author)
+- **journal**: /message/container-title
+  (alternatively if you want the journal abbreviation you can use /message/short-container-title if available)
+- **year**: /message/published/date-parts (index 0 in the JSON array)
+- **volume**: /message/volume
+- **issue**: /message/issue
+- **pages**: /message/page (yes singular)
+
+```{note}
+Looking at this you will see that while the data is available, it is not as logically organized as it could be and 
+there are some formatting issues (for instance the abstract).  This is a consequence of both the CrossRef schema for
+the JSON output, and the approach to populating the metadata of the publisher.  With the focus on open citations in
+the research community I hope that this will soon be addressed.
+```
+
+## 2 Getting and formatting the citation string
+In order to create our citation string on the Google sheet we need to implement a call to the CrossRef URL, for the
+paper retrieval of these metadata fields and some organization and formating. This is implemented in the Google sheet
+in each column, and much of the mechanics is hidden in rows between the showing data.  This is all explained in the
+'How it works' sheet.
+
+![fig](../images/gsheets_citations_howitworks.jpg)
+Caption: The Google Sheets 'How It Works' sheet 
+
+Let's walk through the code.  The Crossref path is in cell B2 and the DOI is added to cell B3.  The full path is
+created in the Google Sheet function 'CONCAT'.  Here is an example call to get the data.
+
+`=ImportJSON(CONCATENATE('How it works'!$B$2,B3),"/message/title","noInherit,noTruncate,rawHeaders")`
+
+The Google Sheet 'ImportJSON' addon [function](https://workspace.google.com/marketplace/app/importjson_import_json_data_into_google/782573720506) 
+takes a URL (first variable) and a path to data (second variable) and optionally
+so processing options (third variable).  When the Google sheet processes this function the data at the path is put into
+the cell below the function.  This works easily for the title, journal name, volume, issue and pages.
+
+In order to process the authors and the year we have to do a little more.  For the authors, the data is a JSON array
+and thus has to be organized to subsequently be able to be put back together as a string.  This is done by loading the
+data (up to eight authors) into columns B and C, concatenating these in column D and finally concatenating non-empty
+cells in B15.  This can be expanded to more authors by adding more space for authors and updating the code to cover
+all the author data.
+
+For the year, as there is no 'year' field, we need to take the publised data parts (year, month, day) as a comma
+separated string (B19) and then get the first four characters of that string to get the year.  It would be easier if the 
+'path' could point to specific elements in the array (i.e. /message/published/date-parts/0), but this does not work.
+
+Finally, our goal of a citation string is implemented in B27, by concatenating the fields above with some extra 
+formatting.  In the 'Worksheet' sheet all the mechanics are hidden and all that is needed is to add a DOI of a
+paper in each/any of B2, C2, or D2 (you can copy any of the B,C or D columns across to other columns to process) 
+metadata for more files.
+
+## 3 Conclusion
+In this brief tutorial you can see how Google Sheets and the ImportJSON addon allows you to process any API data.
+Given this example, you can create spreadsheet views fo API data and even integrate data from multiple sources.
+The only thing to be aware of is that the more calls to APIs that you make in one sheet the slower the over all
+sheet will work, but this of course depends on your access speed, so you may need to optimize how you import the data.