TY - GEN AU - Perera , H.D.B.S. TI - Trend analysis of the use of natural resources in the constraction industry SN - 9559017098 U1 - 333.7 PY - 2002/// CY - Colombo PB - The Deparment of National planning KW - ECONOMICS KW - ENVIRONMENTAL MANAGEMENT-SRI LANKA KW - NATURAL RESOURSES OF SRI LANKA ER -