Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
va thanh » gia thanh, ban thanh, va tinh
sang ma » tang ma, nang ma, sang tao
hieu va » lieu va, hieu qua
cao duc » dao duc, cao suc, giao duc
va hanh » van hanh, va danh, ban hanh
va cao » va cac, va co, va dao
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: thu sach y ((nang x) or (sang ma)) hoi. hieu va cao duc ((va hanh) or (va thanh)) dai cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y ((nang x) OR (sang ma)) hoi. hieu va cao duc ((va hanh) OR (va thanh)) dai cua tu.
• Adding a wildcard symbol may retrieve word variants: thu sach y ((nang x) or (sang ma)) hoi. hieu va cao duc ((va hanh) or (va thanh)) dai cua tu*.