5,250 titles
| Presa | 1923-1924 | Bucharest, Romania |
| Primăria Sibiului | 1992-2002 | Sibiu, Romania |
| Primăvara | 1922-1929 | Sânnicolau Mare, Romania |
| Probleme Ale Păcii și Socialismului | 1959-1979 | Bucharest, Romania |
| Probleme de Informare şi Documentare | 1990-2001 | Bucharest, Romania |
| Problems of control and information theory | 1972-1991 | Budapest, Hungary |
| Proceedings of the Microbiological Research Group of the Hungarian Academy of Sciences | 1966-1970 | Budapest, Hungary |
| Prognosztika | 1969-1987 | Budapest, Hungary |
| Progresul | 1863-1870 | Iași, Romania |
| Proletár | 1920-1920 | Vienna, Austria |
| Pro Minoritate | 1991-2018 | Budapest, Hungary |
| Protestáns Egyházi és Iskolai Lap | 1842-1919 | Budapest, Hungary |
| Protestáns Szemle | 1889-1944 | Budapest, Hungary |
| Provincia | 1972-2001 | Cluj-Napoca, Romania |
| Průboj | 1968-1978 | Ústí nad Labem, Czechia |
| Pszichológia | 1981-2007 | Budapest, Hungary |
| Pszichológiai tanulmányok | 1958-1986 | Budapest, Hungary |
| Publications of Debrecen Heliophysical Observatory of the Hungarian Academy of Sciences | 1964-1990 | Debrecen, Hungary |
| Puszta. A Magyar Madártani Egyesület Évkönyve | 1983-1988 | Budapest, Hungary |
| Ráckevei füzetek | 1967-1992 | Ráckeve, Hungary |
