1. Bourgoyne, A. T. Jr., Millheim, K. K., Chenevert, M. E. and Young, F. S. Jr. 1991.Applied Drilling Engineering, 5354–55. Richardson, TX: Society of Petroleum Engineers.
2. Chilingarian, G. V. and Vorabutr, P. 1983.Drilling and Drilling Fluids,, 1st ed., 149–151. 198301–303. Amsterdam: Elsevier Publishers.
3. New Method of Measuring Gel Strength of Clay-Based Drilling Fluids and the Determination of their Long-Term Gelation Behaviour
4. Gray, G. R. and Darley, H. C. H. 1981.Composition and Properties of Oil Well Fluids,, 4th ed., 11107131Houston, TX: Gulf Publishing.