Perhaps you should try some spelling variations:
thanh tai » thanh hai, thanh toan, doanh tai
van thanh » ban thanh, van tuan
ve triet » va trien, su triet
sach ky » sac ky, sach y, sach ty
cao duc » dao duc, cao suc, giao duc
tu sach » thu sach, su sach, te sach
nang ma » tang ma, sang ma, nang cao
hieu ve » hieu va, hieu van
tai ve » tai va, tai he, tai le

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 ky ((nang ma) or (nang x)) hoi. hieu ve ((cao duc) or (pham duc)) van thanh tai ve triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ky ((nang ma) OR (nang x)) hoi. hieu ve ((cao duc) OR (pham duc)) van thanh tai ve triet.
• Adding a wildcard symbol may retrieve word variants: tu sach ky ((nang ma) or (nang x)) hoi. hieu ve ((cao duc) or (pham duc)) van thanh tai ve triet*.