Penggayaan APA

SEN, Ashish K., SMITH, Tony E.. (1995). Gravity models of spatial interaction behavior . Berlin: Springer-Verlag.

Chicago Style

SEN, Ashish K., SMITH, Tony E.. Gravity models of spatial interaction behavior. Berlin: Springer-Verlag, 1995. Buku.

MLA Style

SEN, Ashish K., SMITH, Tony E.. Gravity models of spatial interaction behavior. Berlin: Springer-Verlag, 1995. Buku.

Turabian Style

SEN, Ashish K., SMITH, Tony E.. Gravity models of spatial interaction behavior. Berlin: Springer-Verlag, 1995. Buku.