1. Watton J. Monitoring the wear characteristics of a positive displacement pump operating with a water-based emulsion. Seminar on Pumps for difficult liquids—mechanical design and performance characteristics, London, 1986, pp. 43–47 (Institution of Mechanical Engineers).
2. Watkins K., Watton J. Wear monitoring of a vane pump using a 60/40 emulsion. Proceedings of Second International Conference on Condition monitoring, London, 1988, pp. 107–116 (BHRA Fluid Engineering Centre).