This graph database has worked well enough that we want to be good at applying it. There are documents that might help.
Graphs for knowledge representation. #63. github 
See Neo4J for our first experiments.
How To Install Neo4J on an Ubuntu VPS.  post 
Cypher query language reference card. doc 
Indices, old style and new. post 
Product recommendations using a hybrid filter. post 
See also neo4j integration with viz. github 
Neo4j offers sandbox accounts that will last a week or so. site 
Visit the trumpworld from the neo4j browser. site 
:play http://guides.neo4j.com/trumpworld
Spring data for generating queries. site 
url parameter for play
Triadic closure is a concept in social network theory. If a strong tie exists between A-B and A-C, there is a weak or strong tie between B-C.  wikipedia 
