Perhaps you should try some spelling variations:
hac thuc » hoc thuc, ha thuc, thach thuc
hieu van » hieu va, thien van, lieu va
vu sach » vu bach, su sach, vu khach
cua tre » cua te, cua triet, dua tren
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
van hac » van hoc, van ha, van hai
nang xa » nang x, lang xa, mang xa
nang ma » tang ma, sang ma, nang cao
cuu tre » cau tren, cau treo

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 y ((nang xa) OR (nang ma)) hoi. hieu van hac thuc va hanh vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach y ((nang xa) OR (nang ma)) hoi. hieu van hac thuc va hanh vi ((cua tre) OR (cuu tre))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach y ((nang xa) OR (nang ma)) hoi. hieu van hac thuc va hanh vi ((cua tre) or (cuu tre))*".