Further reading

• If you want to learn more about the mathematics behind graph theory, you can start with Graph Theory with Applications, J.A. Bondy and U.S.R. Murty, Elsevier, whose first edition is available for free on the web, for instance at https://www.freetechbooks.com/graph-theory-with-applications-t559.
• For more information about choosing the appropriate schema for your graph data, see Neo4j Graph Data Modeling, M. Lal, Packt Publishing.

• Some references to learn more about degrees of separation:

• Paper about the Microsoft study: Planetary-Scale Views on an Instant-Messaging Network by Jure Leskovec and Eric Horvitz
• Facebook research blog post: https://research.fb.com/blog/2016/02/three-and-a-half-degrees-of-separation/