Justus von Liebig (1855). “Principles of agricultural chemistry with special reference to the late researches made in England: By Justus von Liebig. (Ed. by William Gregory)”, p.31
Ambrose Bierce (2011). “Ambrose Bierce: The Devil's Dictionary, Tales, and Memoirs: The Devil's Dictionary, Tales, and Memoirs”, p.720, Library of America
Ernestine Louise Rose (2008). “Mistress of herself: speeches and letters of Ernestine L. Rose, early women's rights leader”, The Feminist Press at CUNY