Citazione APA

Roy, A. E., & Clarke, D. (1978). Astronomy: Structure of the universe. Adams and Higler.

Stile di citazione Chicago

Roy, A E., e D. Clarke. Astronomy: Structure of the Universe. Bristol: Adams and Higler, 1978.

Citazione MLA

Roy, A E., e D. Clarke. Astronomy: Structure of the Universe. Adams and Higler, 1978.