Perhaps you should try some spelling variations:
nam thuoc » nam thuc, nam thu, cay thuoc
nha thuoc » nha nuoc, nhan thuc, nha hoc
hanh hai » thanh hai, nhanh hai, hang hai
su sach » so sach, vu sach
ma hanh » va hanh, da hanh, na hanh
hai cau » hai chau, hai chu, hai hau
hieu va » lieu va, hieu qua
cao hoi » cau hoi, co hoi, cao hoc
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: su sach ((y nang) or (ly nang)) cao hoi. hieu va ((nam thuoc) OR (nha thuoc)) ma hanh hai cau thi~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((y nang) OR (ly nang)) cao hoi. hieu va ((nam thuoc) OR (nha thuoc)) ma hanh hai cau thi.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((y nang) or (ly nang)) cao hoi. hieu va ((nam thuoc) OR (nha thuoc)) ma hanh hai cau thi".
• Adding a wildcard symbol may retrieve word variants: su sach ((y nang) or (ly nang)) cao hoi. hieu va ((nam thuoc) OR (nha thuoc)) ma hanh hai cau thi*.