Stringuetti, C., L. Guilhermino, and Eduardo Mendes da Silva. 2008. “Cholinesterase Activity in the Head of Wild Poecilia Reticulata from Bahia, Brazil: Biochemical Characterization, Effects of Sample Storage and Normal Range of Activity”. Ecotoxicology and Environmental Contamination 3 (1):57-63. https://doi.org/10.5132/jbse.2008.01.009.