Michels, John (1880). John Michels (ed.). Science. Vol. 1. American Association for the Advance of Science. 229 Broadway ave., N.Y.: American Association for the Advance of Science. pp. 2090pp. பன்னாட்டுத் தரப்புத்தக எண்1-930775-36-9.{{cite book}}: CS1 maint: location (link)