Graph theoretic formulation for 3DIR. Book chapter at https://dspace.lboro.ac.uk/2134/28444. In Kumar, B. (ed.). Contemporary Strategies and Approaches in 3-D Information Modeling. Hershey, Pennsylvania: IGI Global, pp.115-135. Book available at https://www.igi-global.com/book/contemporary-strategies-approaches-information-modeling/190536.