This material is licensed under the Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International License.
It basically means you can do whatever you want with the material as long as it's for non-commercial use but you've got to attribute the original author (Vladislav Skurishin) and share any derivative works under the same license.
If you're interested in using the material for commercial purposes or otherwise licensing material, feel free to get in touch at support@vectree.ru.