Nillo Eelis Virkki, Cytogeneticist: In Memoriam (1924-2005)v. 92No. 3-4UNIV PUERTO RICO, AGRICULTURAL EXPERIMENT STATION245–256
Segarra-Carmona, Alejandro E., Santiago-Blay, Jorge A., and Escudero, Jaime. 2008. "Nillo Eelis Virkki, Cytogeneticist: In Memoriam (1924-2005)." Journal of Agriculture of the University of Puerto Rico, 92, (3-4) 245–256.