Perhaps you should try some spelling variations:
thanh vi » hanh vi, thanh va, thanh ve
va thanh » gia thanh, ban thanh, va tinh
nang cai » nang tai, nang cap, nang can
cac luc » cau luc, coc luc, cac nuoc
qua cac » cua cac
cua tre » cua te, cuu tre, cua triet
sanh y » sinh y, anh y, sach y
hanh y » hanh ky, anh y, hanh _
luc va » duc va, tuc va, loc va
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: so ((sanh y) OR (hanh y)) ((nang cai) or (nang cao)) hoi. hieu qua cac luc va thanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so ((sanh y) OR (hanh y)) ((nang cai) OR (nang cao)) hoi. hieu qua cac luc va thanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "so ((sanh y) OR (hanh y)) ((nang cai) or (nang cao)) hoi. hieu qua cac luc va thanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: so ((sanh y) OR (hanh y)) ((nang cai) or (nang cao)) hoi. hieu qua cac luc va thanh vi cua tre*.