Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
va triet » va thiet, va trien, ve triet
hieu van » hieu va, thien van, lieu va
thanh vi » hanh vi, thanh va, thanh ve
nam thuc » nam thuoc, am thuc, nam thu
cam tuc » cam xuc, cam tu, dam thuc
sach ky » sac ky, sach y, sach ty
te sach » toc sach
dang xa » dang xay, lang xa, dang va
dang ha » dong ha, dung ha, lang ha
vi va » vi van, vai va, vu va

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach ky ((dang xa) or (dang ha)) hoi. hieu van ((cam tuc) OR (nam thuc)) van thanh vi va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky ((dang xa) OR (dang ha)) hoi. hieu van ((cam tuc) OR (nam thuc)) van thanh vi va triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky ((dang xa) or (dang ha)) hoi. hieu van ((cam tuc) OR (nam thuc)) van thanh vi va triet".
• Adding a wildcard symbol may retrieve word variants: te sach ky ((dang xa) or (dang ha)) hoi. hieu van ((cam tuc) OR (nam thuc)) van thanh vi va triet*.