Perhaps you should try some spelling variations:
thu sach » thuat sach, thuoc sach, thu hoach
van luat » va luat, dan luat, van luan
van xuat » san xuat, va xuat, phan xuat
tu sach » su sach, te sach, tu cach
nang ma » tang ma, sang ma, nang cao
thuc va » thuc vat, thuc dan, thuc day
va hanh » van hanh, va thanh, va danh
hanh di » hanh vi, hanh de, hang di
ma hoi » mai hoi, xa hoi, ma hoa
di cua » dai cua, doi cua, de cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu sach)) ky nang ma hoi. hieu ((van luat) OR (van xuat)) thuc va hanh di cua vat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky nang ma hoi. hieu ((van luat) OR (van xuat)) thuc va hanh di cua vat.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (thu sach)) ky nang ma hoi. hieu ((van luat) OR (van xuat)) thuc va hanh di cua vat".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky nang ma hoi. hieu ((van luat) OR (van xuat)) thuc va hanh di cua vat*.