Perhaps you should try some spelling variations:
hau treo » cau treo, cau theo, dau tren
van dung » van dong, xay dung, tin dung
van dang » van dong, van nang, van dan
hieu van » hieu va, thien van, lieu va
nang tai » hang tai, tang tai, sang tai
nang mai » nang ma, lang mai, nang cai
sach ly » sach y, sach lo, sach ty
van cam » van nam, van lam, van cau
cam tuc » cam xuc, cam tu, nam thuc
hai hau » hai chau, dai hau, hai hai
vu sach » vu bach, su sach, vu khach

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ly ((nang mai) or (nang tai)) hoi. hieu van cam tuc ((van dang) OR (van dung)) hai hau treo~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ly ((nang mai) OR (nang tai)) hoi. hieu van cam tuc ((van dang) OR (van dung)) hai hau treo.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ly ((nang mai) or (nang tai)) hoi. hieu van cam tuc ((van dang) OR (van dung)) hai hau treo".
• Adding a wildcard symbol may retrieve word variants: vu sach ly ((nang mai) or (nang tai)) hoi. hieu van cam tuc ((van dang) OR (van dung)) hai hau treo*.