00381nam a2200121   4500008004100000020001500041050002200056100003600078245005700114260003200171300003300203650002300236150704b        xxu||||| |||| 00| 0 eng d  a0023224436  aGB 54.5 .C48 1992  aChristopherson, Robert W.d1992  aGeosystems : ban introduction to physical geography  aNew York:bMacmillan,c1992  axxii,616p;illbInclude index  aPhysical geography