Citazione APA

Comstock, G. C. (1901). A text-book of astronomy. D. Appleton and company.

Stile di citazione Chicago

Comstock, George C. A Text-book of Astronomy. New York: D. Appleton and company, 1901.

Citazione MLA

Comstock, George C. A Text-book of Astronomy. D. Appleton and company, 1901.