diff --git a/Makefile b/Makefile
index 6c9d9f21..223a807c 100644
--- a/Makefile
+++ b/Makefile
@@ -63,7 +63,7 @@ upload-test: dist upload-env
 	source .upload_env testing && twine upload --non-interactive --verbose -r testpypi dist/*
 
 install-test:
-	pip install -i https://test.pypi.org/simple/ harmony
+	pip install --index-url https://test.pypi.org/simple --extra-index-url https://pypi.python.org/simple harmony
 
 upload: dist upload-env
 	source .upload_env release && twine upload --non-interactive --verbose -r pypi dist/*
diff --git a/README.md b/README.md
index edb8154c..459746c5 100644
--- a/README.md
+++ b/README.md
@@ -14,6 +14,7 @@ Harmony is a programming language designed for testing and experimenting with co
   - [Updating Harmony](#updating-harmony)
   - [Troubleshooting](#troubleshooting)
     - [Modifying your PATH variable](#modifying-your-path-variable)
+  - [Reading the Source Code](#reading-source)
 
 For more information, please visit the official page https://harmony.cs.cornell.edu.
 
@@ -196,3 +197,7 @@ export PATH=$PATH:/path/to/add/
 Save the file.
 
 You will have to restart Terminal (and VSCode if you are using the extension) to have the changes take effect.
+
+## Reading the Source Code
+
+The compose.pdf file is the beginning of a document explaining how Harmony works.
diff --git a/compose.pdf b/compose.pdf
new file mode 100644
index 00000000..4ee36957
Binary files /dev/null and b/compose.pdf differ