Roy, A. E., & Clarke, D. (1988). Astronomy: : principles and practice (3rd ed.). Bristol: Institute of Physics Publishing.
Παραπομπή Chicago StyleRoy, A. E., and D. Clarke. Astronomy: : Principles and Practice. 3rd ed. Bristol: Institute of Physics Publishing, 1988.
Παραπομπή MLARoy, A. E., and D. Clarke. Astronomy: : Principles and Practice. 3rd ed. Bristol: Institute of Physics Publishing, 1988.
Πρόσοχή: Οι παραπομπές μπορεί να μην είναι 100% ακριβείς.