Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hieu van » hieu va, thien van, lieu va
cua tre » cua te, cuu tre, cua triet
va dung » van dung, va duong, vat dung
cam tuc » cam xuc, cam tu, nam thuc
sach ty » sach y, sach tu, sach thu
su sach » so sach, vu sach
nang ma » tang ma, sang ma, nang cao
van cam » van nam, van lam, van cau
tuc va » thuc va, truc va, tuc xa

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 ty ((nang ma) or (nang x)) hoi. hieu van cam tuc va dung tai ((cua tre) or (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang ma) OR (nang x)) hoi. hieu van cam tuc va dung tai ((cua tre) OR (cau tren)).
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang ma) or (nang x)) hoi. hieu van cam tuc va dung tai ((cua tre) or (cau tren))*.