| #5451 | Optics communications. -- Amsterdam : North-Holland, 1969-. -- ISSN 0030-4018 print. -- ISSN 1873-0310 online |
| #5452 | Optičeskij žurnal. -- Sankt-Peterburg : Gosudarstvennyj optičeskij institut, 1992-. -- ISSN 1023-5086 |
| #5453 | Optik : international journal for light and electron optics. -- Stuttgart : Wissenschaftliche Verlagsgesellschaft, 1946-. -- ISSN 0030-4026 print. -- ISSN 1618-1336 online |
| #5454 | Optiko-mechaničeskaja promyšlennost’. -- Leningrad : Optičeskij institut im. S.I. Vavilova, 1931-1992. -- ISSN 0030-4042 |
| #5455 | OR-Spektrum. -- Berlin : Deutscher Gesellschaft für Operations Research, 1979-. -- ISSN 0171-6468 print. -- ISSN 1436-6304 online |
| #5456 | Oracle. -- Redwood Shores : Oracle Corporation, 1987-. -- ISSN 1065-3171 |
| #5457 | Organ für die Fortschritte des Eisenbahnwesens. -- Berlin : Springer, 1846-1920 |
| #5458 | Organic & biomolecular chemistry : An international journal of all areas of organic, physical organic and biomolecular organic chemistry. -- Cambridge : Royal Society of Chemistry, 2003-. -- ISSN 1477-0520 print. -- ISSN 1477-0539 online |
| #5459 | Organic electronics. -- Amsterdam : North-Holland, 2000-. -- ISSN 1566-1199 print. -- ISSN 1878-5530 online |
| #5460 | Organic letters. -- Columbus : American Chemical Society, 1999-. -- ISSN 1523-7060 print. -- ISSN 1523-7052 online |