| #5521 | Online searcher : information discovery, technology, strategies. -- Medford : Information Today, 2013-. -- ISSN 2324-9684 |
| #5522 | Open computing : McGraw-Hill's magazine of open systems computing. -- San Mateo : McGraw-Hill, 1994-1995. -- ISSN 1078-2370 |
| #5523 | Open systems today : the newspaper of UNIX and interoperable computing. -- Manhasset : CMP Publications, 1992-1995. -- ISSN 1040-5038 |
| #5524 | Open systems today : the newspaper of Unix and Interoperable Computing. -- Spojené státy americké : Manhasset : CMP Publications, Inc, 1992-1995. -- ISSN 1061-0839 |
| #5525 | Operating engineer : operation and maintenance of the power services. -- Spojené státy americké : New York : McGraw-Hill, 1947-1951 |
| #5526 | Operating experience with nuclear power stations in member states in ... -- Vienna : nternational Atomic Energy Agency, 1979-2005. -- ISSN 1011-2642 |
| #5527 | Operational research quarterly. -- Oxford : Pergamon Press, 1970-1977. -- ISSN 0030-3623 |
| #5528 | Operations research. -- Baltimore : The Operations Research Society of America, 1956-. -- ISSN 0030-364X print. -- ISSN 1526-5463 online |
| #5529 | Operative Dienst. -- Německo : Berlin : Transpress, 1957-1965. -- ISSN 0323-8539 |
| #5530 | Operatívne informácie, zváranie. -- Slovensko : Bratislava : Výskumný ústav zváračský, 1962-1973 |