Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
hanh hai » thanh hai, nhanh hai, hang hai
thuoc va » thuc va, thuoc ma, thuong va
cao hoi » cau hoi, co hoi, cao hoc
va hanh » van hanh, va thanh, va danh
hieu va » lieu va, hieu qua
su sach » so sach
ly vang » ly hang, ly van, ly quang
vu sach » vu bach, vu khach
hai cau » hai chau, hai chu, hai hau
va nam » van nam, ha nam, va nay
v nang » va nang, vu nang, van nang

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) or (vu sach)) ((v nang) or (ly vang)) cao hoi. hieu va nam thuoc va hanh hai cau thi~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((su sach) OR (vu sach)) ((v nang) OR (ly vang)) cao hoi. hieu va nam thuoc va hanh hai cau thi.
• Adding a wildcard symbol may retrieve word variants: ((su sach) or (vu sach)) ((v nang) or (ly vang)) cao hoi. hieu va nam thuoc va hanh hai cau thi*.