Hafiz, M. A. A. (1950). Strength characteristics of sands and gravels in direct shear. University of London.
Chicago-viite (17. p.)Hafiz, M. A. A. Strength Characteristics of Sands and Gravels in Direct Shear. University of London, 1950.
MLA-viite (8. p.)Hafiz, M. A. A. Strength Characteristics of Sands and Gravels in Direct Shear. University of London, 1950.
Varoitus: Nämä viitteet eivät aina ole täysin luotettavia.