1. ASTM (American Society for Testing Materials) (1971). Standard method of test for soundness of aggregates by use of sodium sulfate or magnesium sulfate, C88-71a.
2. Bahrain Surface Materials Resources Survey (1978). GeoBooks (in press).
3. British Standards Institution (1971). ‘Specification for media for biological percolating filters’, BS 1438: 1971, Appendix B.
4. Building Research Station (1963). ‘The selection of Portland Stone for various conditions of severity of exposure’, BRE note A112.
5. Salt Weathering in Deserts