R. D.  Lee and Ryckman, R. E., ?Coleoptera and Diptera reared from owl nests?, Bulletin of the Brooklyn Entomological Society, vol. 49, pp. 23-24, 1954.

R. E.  Ryckman, ?Diptera reared from barn owl nests?, Pan-Pacific Entomologist, vol. 29, p. 60, 1953.

R. E.  Ryckman and Ames, C. T., ?Insects reared from cacti in Arizona?, Pan-Pacific Entomologist, vol. 28, pp. 163-164, 1953.