Gaya APA

Rummel, R., G.Hipkin, R. (1990). Gravity, Gradiometry, and Gravimetry . New York: Springer Verlag.

Gaya MLA

Rummel, Reiner., G.Hipkin, Roger. "Gravity, Gradiometry, and Gravimetry". New York: Springer Verlag, 1990. Cetak.