Ortiz, F. J.; Tinaut, A. 1987. Citas nuevas o interesantes de Formícidos (Hym. Formicidae) para Andalucía. Boletín de la Asociación Española de Entomologia 11:31-34. PDF
Ortiz, F. J.; Tinaut, A. 1988. Formícidos del litoral granadino. Orsis (Organismes i Sistemes) 3:145-163.
Osgood, W. H. 1914. Dates for Ovis canadensis, Ovis cervina, and Ovis montana. Proceedings of the Biological Society of Washington 27:1-3.

Notes: Provides evidence on the date of publication of Latreille (1804).

Oster, G. F.; Wilson, E. O. 1978. Caste and ecology in the social insects. Princeton: Princeton University Press, xv + 352 pp.
Oswald, J. D.; Penny, N. D. 1991. Genus-group names of the Neuroptera, Megaloptera and Raphidioptera of the world. Occasional Papers of the California Academy of Sciences 147:1-94. PDF

Notes: Includes a discussion of the dating of Fitch (1855).

Oueslati, W.; Tlili, H.; Nouira, S. 2023. Cataglyphis convexus sp.n., a new ant species (Hymenoptera: Formicidae) in Tunisia. International Journal of Zoology and Animal Biology 6 (4):6 pp. [online early] 10.23880/izab-16000483 PDF
Paaver, K.; Sutt, T. (eds.) 1983. Problems of contemporary Darwinism. [In Russian.]. Tartu: Academy of Sciences of the Estonian SSR, 190 pp.