@misc{Calkins_Gary_Nathan_(1869–1943)_The_1926,
 author={Calkins, Gary Nathan (1869–1943)},
 copyright={Public Domain},
 address={Philadelphia},
 address={New York},
 howpublished={online},
 year={1926},
 publisher={Lea & Febiger},
 language={eng},
 title={The biology of the protozoa},
 URL={http://rcin.org.pl/Content/71602/PDF/WA488_xxxxx_203779_Calkins.pdf},
 keywords={General physiology, Mastigophora, Sarcodina, Infusoria, Sporozoa, Vitality},
}