1. Hendrik van Oss G. Prepared for the US geological survey. Mineral commodity summaries; 2007.
2. Professor Dr. Joseph Davidovits. The history of concrete and the Nabataeans. .
3. Lechtman Heather, Hobbs Linn. Roman concrete and the roman architectural revolution. In: Kingery WD, (editor) Ceramics and civilization volume 3: high technology ceramics: past, present, future. The American Ceramics Society; 1986.
4. The function of entrained air in concrete;Kennedy;J Am Concr Inst,1943
5. The air requirement of frost-resistant concrete;Powers;Proc Highway Res Board,1949