Protozoa ... - Bhatia, B. L. (Bihari Lal), 1884 -1941 (Taylor and Francis, 1936)

The Protozoa - Calkins, Gary N. (Gary Nathan), 1869 -1943 (Macmillan, 1901)

The Protozoa, by Gary N. Calkins - Calkins, Gary N. (Gary Nathan), 1869 -1943 (Macmillan, 1901)

Protozoa in biological research - Calkins, Gary N. (Gary Nathan), 1869 -1943 (Columbia University Press, 1941)

The protozoa of Iowa - Edmondson, Charles Howard, 1876 -1970 (Davenport Academy of Sciences, 1906)

Protozoa of the Devil's Lake complex, North Dakota - Edmondson, Charles Howard, 1876 -1970 (1920)

Protozoa - Schwager, Conrad. (C.F. Winter, 1883)

Protozoa - Schwager, Conrad. (C.F. Winter, 1887)