Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hieu van » hieu va, thien van, lieu va
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
sach ty » sach y, sach tu, sach thu
van cac » van hac, van cau, van bac
cac xuc » cam xuc, cac nuoc, chat xuc
xuc cam » phuc cam
cam dan » cac dan, ca dan, nam dan
cua tre » cua te, cuu tre, dua tren
vu sach » vu bach, su sach, vu khach
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: vu sach ty ((nang xa) or (nang ma)) hoi. hieu van cac xuc cam dan vi ((cua tre) OR (cua triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty ((nang xa) OR (nang ma)) hoi. hieu van cac xuc cam dan vi ((cua tre) OR (cua triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty ((nang xa) or (nang ma)) hoi. hieu van cac xuc cam dan vi ((cua tre) OR (cua triet))".
• Adding a wildcard symbol may retrieve word variants: vu sach ty ((nang xa) or (nang ma)) hoi. hieu van cac xuc cam dan vi ((cua tre) OR (cua triet))*.