Gaya APA

Duffet-Smith, P., Zwart, J. (2011). Practical Astronomy with your Calculator or Spreadsheet Fourth Edition (Fourth Edition). University of Cambridge: Cambridge University Press.

Gaya MLA

Duffet-Smith, Peter., Zwart, Jonathan. "Practical Astronomy with your Calculator or Spreadsheet Fourth Edition". Fourth Edition University of Cambridge: Cambridge University Press, 2011. Buku.