Perhaps you should try some spelling variations:
dau tieng » dau tien, cau tieng, day tieng
nam thuoc » nam thuc, nam thu, nha thuoc
va thanh » gia thanh, ban thanh, va tinh
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
sach ty » sach tu, sach thu, xach tay
va danh » va dinh, va dan, va hanh
va nam » van nam, ha nam, va nay
vi dau » vi dai, va dau, bi dau

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu ((sach ty) OR (sach y)) nang xa hoi. hieu va nam thuoc ((va danh) or (va thanh)) vi dau tieng~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu ((sach ty) OR (sach y)) nang xa hoi. hieu va nam thuoc ((va danh) OR (va thanh)) vi dau tieng.
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu ((sach ty) OR (sach y)) nang xa hoi. hieu va nam thuoc ((va danh) or (va thanh)) vi dau tieng".
• Adding a wildcard symbol may retrieve word variants: thu ((sach ty) OR (sach y)) nang xa hoi. hieu va nam thuoc ((va danh) or (va thanh)) vi dau tieng*.