Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
thanh tai » thanh hai, thanh toan, doanh tai
su sach » so sach, vu sach
sach ly » sach y, sach lo, sach ty
ly nang » ky nang, ly hang, ly vang
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
cua te » cua tu
cua cu » cua chu, cua cau, cua su

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 ly nang xa hoi. hieu ve ((pham duc) or (cao su)) van thanh tai ((cua te) or (cua cu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ly nang xa hoi. hieu ve ((pham duc) OR (cao su)) van thanh tai ((cua te) OR (cua cu)).
• Adding a wildcard symbol may retrieve word variants: su sach ly nang xa hoi. hieu ve ((pham duc) or (cao su)) van thanh tai ((cua te) or (cua cu))*.