5,484 titles
| Communicationes Archaeologicae Hungariae | 1981-2013 | Budapest, Hungary |
| COMPLEX | 1992-2005 | Budapest, Hungary |
| Concordia | 1861-1867 | Budapest, Hungary |
| Confessio | 1977-2011 | Budapest, Hungary |
| Construcția de Maşini | 1963-1990 | Bucharest, Romania |
| Construcţii | 1950-1973 | Bucharest, Romania |
| Constructorul | 1950-1973 | Bucharest, Romania |
| Contemporanul | 1948-2020 | Bucharest, Romania |
| Convieţuirea | 1997-2018 | Szeged, Hungary |
| Convorbiri Literare | 1868-1944 | Bucharest, Romania |
| Corpus Juris Hungarici | Books | |
| Corvina | 1878-1951 | Budapest, Hungary |
| Cotidianul | 1991-2009 | Bucharest, Romania |
| Crișana | 1946-1974 | Oradea, Romania |
| Criticai Lapok | 1992-2022 | Budapest, Hungary |
| Cronica | 1966-2018 | Iași, Romania |
| Cronica Sătmăreană | 1968-1974 | Satu Mare, Romania |
| Család és Iskola | 1875-1917 | Cluj-Napoca, Romania |
| Családi Kör | 1864-1879 | Budapest, Hungary |
| Családi Kör | 1991-2022 | Novi Sad, Serbia |
