Gravity, Specific 4 : The weight of a particular volume of any substance compared to the weight of an equal volume of water at a reference temperature. (Bul 10C)
The Mudblogger (Oilfield, Energy and Related Photographs), Oil Field Glossary, TX, USA 2014. http://mudblogger.com/oilfield-glossary/, (Oil - Amer) {777}