Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
nam thuc » nam thuoc, am thuc, nam thu
dang xay » dang van, van xay
cua tre » cua te, cuu tre, dua tren
thuc xa » thuc xay, tuc xa, thuc va
sach ty » sach y, sach tu, sach thu
su sach » so sach, vu sach
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
va nam » van nam, ha nam, va nay
xa dan » ca dan, xa dai, va dan
dan vi » doan vi, don vi, dan va

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 xa) or (dang xay)) hoi. hieu va nam thuc xa dan vi ((cua tre) or (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang xa) OR (dang xay)) hoi. hieu va nam thuc xa dan vi ((cua tre) OR (cua triet)).
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang xa) or (dang xay)) hoi. hieu va nam thuc xa dan vi ((cua tre) or (cua triet))*.