Das Pflanzenreich :regni vegetablilis conspectus - Engler, Adolf, 1844 -1930 (W. Engelmann, 1937)

Die Pflanzenstoffe, botanisch-systematisch bearbeitet ; chemische Bestandteile und Zusammensetzung der einzelnen Pflanzenarten, Rohstoffe und Produkte. Phanerogamen - Wehmer, C. (Carl), 1858 -1935 (G. Fischer, 1911)

Die Pflanzenwelt Afrikas, insbesondere seiner tropischen Gebiete : Grundzge der Pflanzenverbreitung im Afrika und die Charakterpflanzen Afrikas - Engler, Adolf, 1844 -1930 (W. Engelman, 1910)

Die Pflanzenwelt der peruanischen Anden in ihren Grundzügen dargestellt - Weberbauer, A. (August), 1871 -1948 (W. Engelmann, 1911)

Die Pflanzenwelt Ost-Afrikas und der Nachbargebiete - Engler, Adolf, 1844 -1930 (D. Reimer, 1895)

Phanerogamic flora of the divisions of Uitenhage and Port Elizabeth : with a sketch map - Schönland, S. 1860 - (Govt. Print. and Stationery Office, 1919)

The phanerogams of the Juan Fernandez Islands - Skottsberg, Carl, 1880 -1963 (1921)

Pharmaceutical botany; a text-book for students of pharmacy and science - Youngken, Heber W. (Heber Wilkinson), 1885 -1963 (P. Blakiston's son & co, 1920)

Pharmaceutical botany, with glossary of botanical terms - Youngken, Heber W. (Heber Wilkinson), 1885 -1963 (Blakiston, 1921)

The pharmacopoeia of another botanical physician - Riddell, William Renwick, 1852 -1945 (Botanical Society of Edinburgh?, 1919)

The Philippine journal of science - Philippines. National Science Development Board. (Bureau of Science, 1912)

The Philippine journal of science - Philippines. National Science Development Board. (Bureau of Science, 1915)

Philosophical transactions of the Royal Society of London - Royal Society (Great Britain) (Royal Society of London, 1883)

Physis - Sociedad Argentina de Ciencias Naturales. (Asociación Argentina de Ciencias Naturales [etc.], 1915)

Physis - Sociedad Argentina de Ciencias Naturales. (Asociación Argentina de Ciencias Naturales [etc.], 1918)

Physis - Sociedad Argentina de Ciencias Naturales. (Asociación Argentina de Ciencias Naturales [etc.], 1921)

Phytogeographic studies in the Peace and upper Liard river regions, Canada, with a catalogue of the vascular plants - Raup, Hugh M. (Hugh Miller), 1901 -1995 (Arnold Arboretum of Harvard university, 1934)

Phytogeographic survey of North America. A consideration of the phytogeography of the North American continent, including Mexico, Central America and the West Indies, together with the evolution of North American plant distribution - Harshberger, John W. (John William), 1869 -1929 (W. Engelmann, 1911)

Phytogeography of Nebraska. 1. General survey by Roscoe Pound and Frederic E. Clements - Clements, Frederic E. (Frederic Edward), 1874 -1945 (Published by the Seminar, 1900)