Authors
- Oldberg, Oscar, 1846-1913, author1
- Oliphant, H. N. (Homer Newton), 1880-1924 author, publisher1
- Olive, A. H. (Alfred Henderson), 1877- author3
- Oliveira, Alfredo Clodoaldo de, author1
- Oliveira, Almir Sá Cardoso de, author1
- Oliveira, Americo Vespucio Ribeiro d', author1
- Oliveira, Diocleciano Alves de, author1
- Oliveira, Eduardo José de, author1
- Oliveira, Ezequiel Antunes de, author1
- Oliveira, Francisco Rodrigues d', author1
- Oliveira, Luiz Soares de, author1
- Oliveira, Oscar Claudio de, author1
- Oliveira, Oswaldo Rodrigues de, author1
- Oliveira, Raul Fernandes de, author1
- Olmstead, Rossiter D. (Rossiter David), 1894-1974, author1
- Ontario, enacting jurisdiction.2
- Opie, Eugene L. (Eugene Lindsay), 1873-1971 author1
- Oppenheimer, Bernard S.1
- Orcutt, Philip Dana, author1
- Oregon State Joint Committee for Health and Physical Fitness. Bibliography Committee.1
