1. High rate sucker-rod pumping and its economics;Clegg,1996
2. Kuhns JP, Rizzone ML. Well-pumping apparatus. US Patent 3,285,081; 1966.
3. Metters EW. A new concept in pumping unit technology. Paper SPE 3193 presented at the Hobbs petroleum technology symposium held in Hobbs, New Mexico, October 29–30, 1970.
4. Gault RH. Longstroke pumping apparatus for oil wells. US Patent 4,076,218; 1978.
5. The 40-foot stroke, Winch type pumping Unit;Gault,1977