List of references by intial letter. Not all the references are complete or correct. If you have more or better information, please let me know.

P, Maria E. ; 2000; Yaguarasaurus columbianus (Reptlilia, Mosasaurdidae), a Primitive Mosasaur from the Turonian (Upper Cretaceous) of Columbia; Historical Biology; 14: pp.121-131:
Palmer, C. P. ; 1987; The Kimmeridgian fauna associated with the Portland plesiosaur; Proceedings - Dorset Natural History & Archaeological Society; 109: pp.109--112:
Panko, L. J. ; 1997; The synapsid backbone from pelycosaurs to therian mammals: patterns of morphology.; Journal of Vertebrate Paleontology; 17:3: pp.68A:
Papazzoni, Cesare A. ; 2003; A pliosaurid tooth from the Argille Varicolori Formation near Castelvecchio di Prignano (Modena Province, northern Italy); Rivista Italiana di Paleontologia e Stratigrafia (November 2003); 109:6: pp.563-565:
Parris, David C. ; 1974; Additional records of plesiosaurs from the Cretaceous of New Jersey}; Journal of Paleontology; 48:1: pp.32-35:
Paton, R. L. ; 1975; ?; ?;
Perkins, Sid ; 2001; Turn your head and roar; can diagnosing disease in fossils shed light on modern maladies?; Science News (Washington); 160:24: pp.376--378:
Persson, Per Ove ; 1959; Reptiles from the Senonian (Upper Cretaceous) of Scandia (S. Sweden); Arkiv for Mineralogi och Geologi; 2: pp.431-478:
Persson, Per Ove ; 1960; Lower Cretaceous plesiosaurians (Rept.) from Australia.; Lunds Unveristets Arsskrift; 56:12: pp.12-23:
Persson, Per Ove ; 1962; Plesiosaurians from Spitsbergen; Norsk Polarinstitutt Årbok 1961; pp.63-69:
Persson, Per Ove ; 1963; ; ?;
Persson, Per Ove ; 1963; A revsion of the classification of the Plesiosauria with a synopsis of the stratigraphical and geographical distribution of the group; Lunds Unveristets Arsskrift; 59: pp.1-59:
Persson, Per Ove ; 1967; New finds of plesiosaurian remains from the Cretaceous of Scania.; Geol. Foeren. Stockholm; 89:1: pp.67-73:
Persson, Per Ove ; 1982; Elasmosaurid skull from the Lower Cretaceous of Queensland (Reptilia; Sauropterygia); Memoirs of the Queensland Museum; 20, Part 3: pp.647--655:
Persson, Per Ove ; 1990; A plesiosaurian bone from a Cretaceous fissure-filling in NE Scania, Sweden; Geologiska Foereningen i Stockholm Foerhandlingar; 112, Part 2: pp.141--142:
Persson, Per Ove ; 1993; Cretaceous plesiosaurs; Lund Publications in Geology; 109: pp.25:
Persson, Per Ove ; 1996; A crushed reptile skull provisionally referred to Scanisaurus sp; GFF; 118:2: pp.111--112:
Peyer, B. ; 1931; ?; ;
Peyer, B. ; 1933; ?; ?;
Peyer, B. ; 1939; ?; ;
Phillipi ; 1887; ?; ?;
Phillips, J. ; 1853; Report of the council of the Yorkshire Philosophical Society, etc; Ann. Yorks. Philos. Soc.; pp.7-9-8, 19-20:
Phillips, J. ; 1854; On a new Plesiosaurus in the York Museum; Annual report of the British Society for the Advancement of Science; pp.54:
Phillips, J. ; 1854b; Rhomaleosaurus zetlandicus; ;
Phillips, J. ; 1871; Geology of Oxford and the Valley of the ThamesOxfordpp 523pp
Pickles, Graham ; 2000; Whitby Museum - email (private correspondence)
Picte and Camiche ; 1860; Description des fossiles du Terrain Crétacé des Environs de Saint-Croix; ?;
Picte and Renvier ; 1854; ?; ?;
Pinna, Giovanni ; 1974; Il calco di Plesiosaurus hawkinsi Owen, 1840 del Lias inferiore di Lyme Regis esposto al Museo Civico di Storia Naturale di Milano; Natura (Milano); 65:1-2: pp.49--52:
Pinna, Giovanni ; 1992; Cyamodus hildegardis PEYER 1931 (Reptilia, Placodontia); manuscript copy;
Pinna, Giovanni and Peichel, Catherine L ; 1989; Anatomy, functional morphology and paleoecology of the placodont reptile Psephodermia alpium MEYER 195; manuscript copy;
Powel, H. Phillip and Edmonds, J. M. ; 1978; List of type-fossils in the Philpot Collection, Oxford University Museum; Proceedings of the Dorset Natural History and Archaeology Society - Natural History Reports (Geology); 98: pp.48-53:
Pravoslavlev ; 1915; ; ;
Pravoslavlev ; 1916; [Elasmosaurs from the Upper Cretaceous deposits of the Don Region]; Trudy Sankt-Petersburgskogo Osbshchestva Estestvoispyatelei; 48: pp.153-322:
Pravoslavlev ; 1918; [Geological distribution of the Elasmosaurs]; Izvestiya Rossiiskoi AN. VI Seriya; 12: pp.2325-2343:
Pyrah, B. J. ; 1879; Catalogue of the type and figured fossils in the Yorkshire Museum; Proceedings of the Yorkshire Geological Society; 42: pp.415-437: