Cita APA (7th ed.)

Walker, G. (1987). Astronomical observations: An optical perspective. Cambridge University Press.

Cita Chicago (17th ed.)

Walker, G. Astronomical Observations: An Optical Perspective. Cambridge: Cambridge University Press, 1987.

Cita MLA (9th ed.)

Walker, G. Astronomical Observations: An Optical Perspective. Cambridge University Press, 1987.