Gaya APA

WALTHAM, T, B, F, C, M. (2010). Sinkholes and Subsidence: Karst and Cavernous Rocks in Engineering and Construction . : Praxis Publishing Ltd..

Gaya MLA

WALTHAM, Tony;, BELL,, Fred;, CULSHAW,, Martin. "Sinkholes and Subsidence: Karst and Cavernous Rocks in Engineering and Construction". : Praxis Publishing Ltd., 2010. Buku.