1. Al Jassar SH, Hawkins AB (1977) Some geotechnical properties of the main carbonate lithologies within the Carboniferous limestone formation of the Clifton Gorge, Bristol. In: Proceedings of conference on rock engineering, Newcastle upon Tyne, pp 393–405
2. Al Jassar SH, Hawkins AB (1979) Geotechnical properties of the Carboniferous limestone of the Bristol area—the influence of petrography and chemistry. In: 4th conference on international society for rock mechanics, Montreaux, vol 1, pp 3–14
3. American Society for Testing and Materials (1991) ASTM D2938-86/95 standard test method for unconfined compressive strength of intact rock core specimens
4. American Society for Testing and Materials (2000) ASTM D4543-85 practice for preparing rock core specimens and determining dimensional and shape tolerances
5. American Society for Testing and Materials (2013) ASTM D7012-13 Standard test methods for compressive strength and elastic moduli of intact rock core specimens under varying states of stress and temperatures. West Conshohocken, PA