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

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 nam) OR (ha 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 nam) OR (ha 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 nam) OR (ha 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 nam) OR (ha nam)) thuoc va hanh hai cau theo*.