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Petroleum Extension Service & Internat. Associat. of Drilling
Contractors
In:
Lessons in well servicing and workover - Lesson 3, 6th impression 1981, Austin,
Texas, Petroleum Extension Service & Internat. Associat. of Drilling
Contractors, vol. 339-350, no. 11, pp. 253-257, (ISBN 3-933346-037)