00602nam a2200217Ia 4500 CTU_27627 210402s9999 xx 000 0 und d 631 W927/N84 FAO World soil resources reports N84 World reference base for soil resources FAO Rome FAO 1998 Phân loại đất và bản đồ đất NN696 soil maps Nguyễn Quang Điền, 981230 Trung tâm Học liệu Trường Đại học Cần Thơ