Perhaps you should try some spelling variations:
nam thuoc » nam thu, nha thuoc, cay thuoc
cua viet » ca viet, hoa viet, cua vat
tang van » dang van, hoang van, trong van
nam thuc » am thuc, nam thu, nam tu
va hanh » van hanh, va thanh, va danh
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
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 ty ((mang may) or (tang van)) hoi. hieu ve ((nam thuc) or (nam thuoc)) va hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((mang may) OR (tang van)) hoi. hieu ve ((nam thuc) OR (nam thuoc)) va hanh vi cua viet.
• Adding a wildcard symbol may retrieve word variants: su sach ty ((mang may) or (tang van)) hoi. hieu ve ((nam thuc) or (nam thuoc)) va hanh vi cua viet*.