E. V. da Silva-Matos and C. A. Garófalo, “Worker life tables, survivorship, and longevity in colonies of <i>Bombus (Fervidobombus) atratus</i> (Hymenoptera: Apidae)”, Rev. Biol. Trop., vol. 48, no. 2-3, pp. 657–664, Dec. 2000.