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Skelton, James; Farrell, Kaitlin J.; Creed, Robert P.; Williams, Bronwyn W.; Ames, Catlin; Helms, Brian S.; Stoekel, James; Brown, Bryan L. (2013). "Servants, scoundrels, and hitchhikers: current understanding of the complex interactions between crayfish and their ectosymbiotic worms (Branchiobdellida)". Freshwater Science. 32 (4): 1345–1357. doi:10.1899/12-198.1. S2CID86614891.
Wyman, Richard L.; Ward, Jack A. (1972). "A cleaning symbiosis between the cichlid fishes Etroplus maculatus and Etroplus suratensis. I. Description and possible evolution". Copeia. 1972 (4): 834–838. doi:10.2307/1442742. JSTOR1442742.
Wyman, Richard L.; Ward, Jack A. (1972). "A cleaning symbiosis between the cichlid fishes Etroplus maculatus and Etroplus suratensis. I. Description and possible evolution". Copeia. 1972 (4): 834–838. doi:10.2307/1442742. JSTOR1442742.
Macfarland, Craig G.; Reeder, W. G. (1974). "Cleaning symbiosis involving Galapagos tortoises and two species of Darwin's finches". Zeitschrift für Tierpsychologie. 34 (5): 464–483. doi:10.1111/j.1439-0310.1974.tb01816.x. PMID4454774.
Skelton, James; Farrell, Kaitlin J.; Creed, Robert P.; Williams, Bronwyn W.; Ames, Catlin; Helms, Brian S.; Stoekel, James; Brown, Bryan L. (2013). "Servants, scoundrels, and hitchhikers: current understanding of the complex interactions between crayfish and their ectosymbiotic worms (Branchiobdellida)". Freshwater Science. 32 (4): 1345–1357. doi:10.1899/12-198.1. S2CID86614891.