Original RIP method:

http://boscoh.com/rip/
Reference: "Probing the Flexibility of Large Conformational Changes in Protein Structures through Local Perturbations" by Bosco K. Ho and David A. Agard. PLoS Comput Biol 5(4): e1000343.

L-RIP & RIPlig methods:

Reference: Kokh, D. B., Czodrowski, P., Rippmann, F., & Wade, R. C. (2016). Perturbation approaches for exploring protein binding site flexibility to predict transient binding pockets. Journal of chemical theory and computation, 12(8), 4100-4113. DOI: 10.1021/acs.jctc.6b00101