| #861 | Primenenije matematiki v ekonomike. -- Leningrad : Izdatel´stvo Leningradskogo universiteta, 1963-. -- ISSN 0321-267X |
| #862 | PRIMUS : Problems, Resources, and Issues in Mathematics Undergraduate Studies. -- Terre Haute : Rose-Hulman Institute of Technology, 1991-. -- ISSN 1051-1970 print. -- ISSN 1935-4053 online |
| #863 | Probabilistic engineering mechanics. -- Barking : Computational Mechanics Publication, 1985-. -- ISSN 0266-8920 print. -- ISSN 1878-4275 online |
| #864 | Probability and Mathematical Statistics. -- Warszawa; Wrocław : Polish Scientific Publishers, 1980-. -- ISSN 0208-4147 |
| #865 | Probability theory and related fields. -- Heidelberg : Springer, 1986-. -- ISSN 0178-8051 print. -- ISSN 1432-2064 online |
| #866 | Problemy matematičeskoj fiziki. -- Leningrad : Izdatelʹstvo Leningradskogo universiteta. -- ISSN 0555-2818 |
| #867 | Proceedings. -- London : Royal Society, 1990-1996. -- ISSN 0962-8444 |
| #868 | Proceedings, Section A. Mathematics. -- Edinburgh : Royal Society of Edinburgh, 1974-. -- ISSN 0308-2105 |
| #869 | Proceedings in applied mathematics & mechanics. -- : John Wiley and Sons, 2002-. -- ISSN 1617-7061 |
| #870 | Proceedings of A. Razmadze Mathematical Institute. -- Tbilisi : GCI Publishing House, 1994-. -- ISSN 1512-0007 |