1. G. W. Rowe : An Introduction to the Principles of Metalworking. St. Martin's Press ( 1965 ) Chapter II 265/282.
2. M. B. Peterson and F. F. Ling : Friction and Lubrication in Hot Metal Deformation, MTI-66-TR-18, Contract NOw 65-0363-c (March 20, 1966 ) Mechanical Technology Inc.
3. E. H. Roland : Final Report on Evaluation of New and Improved Forging Lubricants, AFML-TR-68-296, Contract AF 33 (615)-3857 (October, 1968 ) TRW Inc.