Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
hanh thai » nhanh thai, hinh thai, hanh tai
hieu van » hieu va, thien van, lieu va
nang ma » tang ma, sang ma, nang cao
sach ty » sach y, sach tu, sach thu
van bac » van ban, van bao, van hac
va hanh » van hanh, va thanh, va danh
nang xa » nang x, lang xa, mang xa
cua tre » cua te, cuu tre, dua tren
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 ty ((nang xa) OR (nang ma)) hoi. hieu van bac duc va hanh thai ((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 bac duc va hanh thai ((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 bac duc va hanh thai ((cua tre) or (cua triet))".
• Adding a wildcard symbol may retrieve word variants: vu sach ty ((nang xa) OR (nang ma)) hoi. hieu van bac duc va hanh thai ((cua tre) or (cua triet))*.