Perhaps you should try some spelling variations:
thuat sach » thuat lanh, thuat san
danh kem » hanh kem, banh kem, danh kien
cua viet » ca viet, cua vat, cua dieu
nang ma » tang ma, nang cao, mang may
sang ma » tang ma, sang tao, mang may
hieu va » lieu va, hieu qua
va danh » va dinh, va dan, va hanh
va dau » va dao

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

• If you are trying to use Boolean operators, they must be ALL CAPS: thuat sach y ((nang ma) OR (sang ma)) hoi. hieu va dau tu va danh kem ((cua viet) OR (hoa viet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thuat sach y ((nang ma) or (sang ma)) hoi. hieu va dau tu va danh kem ((cua viet) OR (hoa viet))~".
• Adding a wildcard symbol may retrieve word variants: thuat sach y ((nang ma) or (sang ma)) hoi. hieu va dau tu va danh kem ((cua viet) OR (hoa viet))*.