1. Albrecht , S. C. and Thompson , E. R. , 1982 . Impact of surface mining on soil compaction in the midwestern USA . US Bureau of Mines , Final Report, Contract J0208016 .
2. Anon. , 1979 . Federal Register , vol. 44 , No. 50 , March 13,1979 , pp. 15312 – 15463
3. Chapin , F. S. , Jr. ' 1979 .Urban Land Use Planning, 3rd edition , University of Illinois Press , Urbana , IL , p. p82 p.