| #611 | The Prague Bulletin of Mathematical Linguistics. -- Praha : Charles University, 1964-. -- ISSN 0032-6585 |
| #612 | Prikladnaâ matematika i mehanika. -- Moskva : Nauka, 1936-. -- ISSN 0032-8235 |
| #613 | Prikladnaâ mehanika. -- Kijev : Institut mechaniky NAN Ukrainy, 1965-. -- ISSN 0032-8243 |
| #614 | Probability and Mathematical Statistics. -- Warszawa; Wrocław : Polish Scientific Publishers, 1980-. -- ISSN 0208-4147 |
| #615 | Problems of control and information theory. -- Budapest : Akadémiai Kiadó, 1972-1991. -- ISSN 0370-2529 |
| #616 | Problemy peredači informacii. -- Moskva : Nauka, 1965-. -- ISSN 0555-2923 |
| #617 | Proceedings, Section A. Mathematics. -- Edinburgh : Royal Society of Edinburgh, 1974-. -- ISSN 0308-2105 |
| #618 | Proceedings of A. Razmadze Mathematical Institute. -- Tbilisi : GCI Publishing House, 1994-. -- ISSN 1512-0007 |
| #619 | Proceedings of the American Mathematical Society. -- Providence : American Mathematical Society, 1950-. -- ISSN 0002-9939 print. -- ISSN 1088-6826 online |
| #620 | Proceedings of the Cambridge philosophical society : Mathematical and physical sciences. -- London : Cambridge University Press, 1866-1974. -- ISSN 0008-1981 |