1. Basu, A., Das, S., Ghosh, S., Sen, M.: Circular arc bigraphs and its subclasses. J. of Graph Theory (73), 361–376 (2013)
2. Brown, D.E., Lundgren, J.R.: Characterization for unit interval bigraphs. In: Proceedings of the Forty-First Southeastern International Conference on Combinatorics, Graph Theory and Computing. Congr. Number. 206, 517 (2010)
3. Brown, D.E., Lundgren, J.R., Flink, S.C.: Characterization of interval bigraphs and unit interval bigraphs. Congress Number (2002)
4. Das, A.K., Chakraborty, R.: New characterization of proper interval bigraphs. Accepted for Publication in International Journal of Graphs and Combinatorics 12(1) (June 2015)
5. Das, A.K., Das, S., Sen, M.K.: Forbidden substructure of interval (bi/di) graphs. Submitted to Discrete Math. (2014)