Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, nha thuoc
cau theo » cau thi, cau tao
hanh hai » thanh hai, nhanh hai, hang hai
thuoc va » thuc va, thuoc ma, thuong va
hai cau » hai chau, hai chu, hai hau
va hanh » van hanh, va thanh, va danh
so sach » so sanh, bo sach, co sach
hieu va » lieu va
ly nang » ky nang, ly hang, ly vang
y nang » ky nang, v nang, may nang

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach ((y nang) or (ly nang)) cau hoi. ((hieu va) OR (hieu qua)) nam thuoc va hanh hai cau theo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach ((y nang) OR (ly nang)) cau hoi. ((hieu va) OR (hieu qua)) nam thuoc va hanh hai cau theo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so sach ((y nang) or (ly nang)) cau hoi. ((hieu va) OR (hieu qua)) nam thuoc va hanh hai cau theo".
• Adding a wildcard symbol may retrieve word variants: so sach ((y nang) or (ly nang)) cau hoi. ((hieu va) OR (hieu qua)) nam thuoc va hanh hai cau theo*.