Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
sach ty » sach tu, sach thu, xach tay
nang ma » tang ma, sang ma, nang cao
tuc van » thuc van, truc van, tuc va
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
ma hoi » mai hoi, xa hoi, ma hoa
qua ca » qua cac, qua cua, qua cai
ca tuc » cua tuc, va tuc
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: su ((((sach ty) or (sach y))) or (sac ky)) nang ma hoi. hieu qua ca tuc van hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((((sach ty) OR (sach y))) OR (sac ky)) nang ma hoi. hieu qua ca tuc van hanh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: su ((((sach ty) or (sach y))) or (sac ky)) nang ma hoi. hieu qua ca tuc van hanh vi cua tre*.