O’Hern, J. E.; Sculley, M.; Jean-Smith, K.; Biggs, D.; Slowey, N.; Alarcon Ruales, D.; Duncan, R. Marine Mammal Distribution in Ecuador: Surveys Aboard a Ship of Opportunity As a Means of Monitoring Relative Abundance. Lat. Am. J. Aquat. Mamm. 2018, 12, 28-39.