Perhaps you should try some spelling variations:
lam thuoc » nam thuoc, am thuc, cay thuoc
cua viet » ca viet, hoa viet, cua vat
thu sach » thuat sach, thuoc sach, thu hoach
van hanh » van thanh, ban hanh, van anh
va hanh » va thanh, va danh, ban hanh
tu sach » su sach, te sach, tu cach
tang ma » mang may, tang van
ky tang » ky nang, ky dang, kho tang
hieu va » lieu va, hieu qua
va lam » van lam, va lap
ma hoi » mai hoi, xa hoi, ma hoa
di cua » dai cua, doi cua, de cua

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((tu sach) or (thu sach)) ky tang ma hoi. hieu va lam thuoc ((va hanh) or (van hanh)) di cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (thu sach)) ky tang ma hoi. hieu va lam thuoc ((va hanh) OR (van hanh)) di cua viet.
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (thu sach)) ky tang ma hoi. hieu va lam thuoc ((va hanh) or (van hanh)) di cua viet*.