1T. K. Perkins, L. R. Kern: Width of hydraulic fracture. JPT, 1961, vol. 13: 937-949.
2S. A. Khristianovie, Y. R Zheltov. Formation of vertieal fractures by means of highty viscous, Iiquid. Proeeedings of the Fourth Wbrld. Petroleum. Congress, Seetion. Ⅱ, PaPer No. 3.