1. 2See reference- (4) of Bibliography on p. 6, this issue.
2. 3See reference (7) of Bibliography.
3. 4See reference (1) of Bibliography.
4. 5(a) J. D. Bernal , "Structures of Cement Hydration Compounds ,"Proc. Intern. Symposium Chemistry of Cement, 3rd Symposium, London, 1952 , pp. 210 -60 (1952 );Ceram. Abstr., 1952 , p. 210 .