Perhaps you should try some spelling variations:
thuc dung » thuoc dung, thuy dung, tuc dung
thuc dang » thuoc dang, thuc dan, thu dang
hanh vai » hanh vi, hanh va, hanh tai
su sach » so sach, vu sach
ky lang » ky nang, ky dang, ky tang
hieu ca » hieu cac, hieu cua, hieu va
sach ky » sac ky, sach y, sach ty
ca nam » cua nam, cai nam, ha nam
ha hoi » hoa hoi, xa hoi, va hoi
vai va » mai va, dai va, hai va
thiet* » thieu*

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ky lang ((ha hoi) OR (ha noi)). hieu ca nam ((thuc dang) or (thuc dung)) hanh vai va thiet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky lang ((ha hoi) OR (ha noi)). hieu ca nam ((thuc dang) OR (thuc dung)) hanh vai va thiet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky lang ((ha hoi) OR (ha noi)). hieu ca nam ((thuc dang) or (thuc dung)) hanh vai va thiet*".