| #51 | Limnology. -- Tokyo : Springer, 2000-. -- ISSN 1439-8621 print. -- ISSN 1439-863X online |
| #52 | Meteorologija i gidrologija. -- Moskva : Gidrometeoizdat, 1935-. -- ISSN 0130-2906 |
| #53 | Morskoj gidrofizičeskij žurnal. -- Kyjev : Naukova Dumka, 1985-. -- ISSN 0233-7584 |
| #54 | Nase More. -- Dubrovnik : Sveučilište, 1919-. -- ISSN 0469-6255 |
| #55 | National driller. -- Troy : Business News Pub. Co., 1999-. -- ISSN 1527-1501 |
| #56 | Nordic hydrology. -- Lyngby : Nordic Association for Hydrology, 1970-2007. -- ISSN 0029-1277 print. -- ISSN 1996-9694 online |
| #57 | Ocean news & technology. -- Palm City : Technology Systems Corp., 1995-. -- ISSN 1082-6106 |
| #58 | Oceans. -- San Francisco : Oceanic Society, 1969-1989. -- ISSN 0029-8174 |
| #59 | Podzemná voda. -- Bratislava : Slovenská asociácia hydrogeológov, 1995-. -- ISSN 1335-1052 |
| #60 | Power technology and engineering. -- New York : Kluwer Academic, 2002-. -- ISSN 1570-145X print. -- ISSN 1570-1468 online |