Gaya APA

Westen, C, V. (1993). Training Package for Geographic Information Systems in Slope Instability Zonation; Part 1 Theory . Netherlands: ITC Publication Number 15.

Gaya MLA

Westen, C.J., Van. "Training Package for Geographic Information Systems in Slope Instability Zonation; Part 1 Theory". Netherlands: ITC Publication Number 15, 1993. Text.