Dantas, JM, Portela PC, Fernandes AP, Londer YY, Yang X, Duke NEC, Schiffer M, Pokkuluri RP, Salgueiro CA.  2019.  Structural and Functional Relevance of the Conserved Residue V13 in the Triheme Cytochrome PpcA from Geobacter sulfurreducens. The Journal of Physical Chemistry B. 123:3050-3060., Number 14