Philippines. Environmental Management Bureau Department of Environment and Natural Resources. (1992). DENR Administrative Order no. 21, Series of 1992: Amending the revised rules and regulations implementing P.D. 1586 : environmental impact assessment system. Environmental Management Bureau, Department of Environment and Natural Resources.
Citazione stile Chigago Style (17a edizione)Philippines. Environmental Management Bureau Department of Environment and Natural Resources. DENR Administrative Order No. 21, Series of 1992: Amending the Revised Rules and Regulations Implementing P.D. 1586 : Environmental Impact Assessment System. [Quezon City]: Environmental Management Bureau, Department of Environment and Natural Resources, 1992.
Citatione MLA (9a ed.)Philippines. Environmental Management Bureau Department of Environment and Natural Resources. DENR Administrative Order No. 21, Series of 1992: Amending the Revised Rules and Regulations Implementing P.D. 1586 : Environmental Impact Assessment System. Environmental Management Bureau, Department of Environment and Natural Resources, 1992.