Perhaps you should try some spelling variations:
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
hac thuc » hoc thuc, ha thuc, thach thuc
hieu van » hieu va, thien van, lieu va
sach tu » sach thu, cach tu, sach ty
thuc va » thuc vat, thuc dan, thuc day
van hac » van hoc, van ha, van hai
cua tre » cua te, cuu tre, cua triet
ma hoi » mai hoi, xa hoi, me hoi
sac ky » cac ky, sai ky
vi cua » vai cua, di cua

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 tu) or (sac ky)) nang ((ma hoi) OR (ma hoa)). hieu van hac thuc va thanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu ((sach tu) OR (sac ky)) nang ((ma hoi) OR (ma hoa)). hieu van hac thuc va thanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu ((sach tu) or (sac ky)) nang ((ma hoi) OR (ma hoa)). hieu van hac thuc va thanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: vu ((sach tu) or (sac ky)) nang ((ma hoi) OR (ma hoa)). hieu van hac thuc va thanh vi cua tre*.