Perhaps you should try some spelling variations:
cay thuoc » cua thuoc, nam thuoc, va thuoc
cua viet » ca viet, hoa viet, cua vat
nam thuc » nam thuoc, am thuc, nam thu
va hanh » van hanh, va thanh, va danh
sach tu » sach thu, cach tu, sach ty
su sach » so sach, vu sach
mai hoi » mai khoi, dai hoi, lai hoi
tu tang » tuc tang, tu trang, tu tong
hieu ve » hieu va, hieu van
ma hoi » xa hoi, ma hoa, me hoi
vi cua » vai cua, di cua

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 tu tang ((ma hoi) OR (mai hoi)). hieu ve ((nam thuc) or (cay thuoc)) va hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu tang ((ma hoi) OR (mai hoi)). hieu ve ((nam thuc) OR (cay thuoc)) va hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach tu tang ((ma hoi) OR (mai hoi)). hieu ve ((nam thuc) or (cay thuoc)) va hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: su sach tu tang ((ma hoi) OR (mai hoi)). hieu ve ((nam thuc) or (cay thuoc)) va hanh vi cua viet*.