Coelho, Paulo Marcos Z., et al. “The Crowding Effect in Schistosoma Mansoni Infection of Hamsters: Influence on Worm Size”. Revista Do Instituto De Medicina Tropical De São Paulo, vol. 18, no. 6, Dec. 1976, pp. 440-2, https://www.revistas.usp.br/rimtsp/article/view/198304.