Pritchard, M A . A systems approach to forest operations planning and control / edited by M.A. Pritchard. - London : Her Majesty`s Stationery Office , 1989. - 157p. : ills ; 23cm . NULL ISBN: 0117102725 UKP 12.00 Subjects--Index Terms: FORESTRY Dewey Class. No.: 634.9 / PRI/S