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3. M. R. Leshukov, "Experimental investigations of the behavior of a pile under oblique extracting loads," in: Architecture and Structural Designs of Industrial Buildings [in Russian], Sverdlovsk (1969).
4. A. Awad and G. Petrasovits, "Consideration of the bearing capacity of vertical and batter piles subjected to forces acting in different directions," in: Proceedings of the 3rd Budapest Conferences on Soil Mechanics and Foundation Engineering, Budapest (1968).