Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
sach ty » sach y, sach tu, sach thu
hieu va » lieu va, hieu qua
cam luc » cam xuc, cau luc
luc van » luoc van, luu van, duc van
kem cua » em cua, keo cua, diem cua
cua tre » cua te, cuu tre, cua triet
sac ky » cac ky, sai ky
va cam » va cham, va cac, va cao
x hoi » o hoi, x ho, 5 hoi

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: te ((sach ty) or (sac ky)) nang ((x hoi) or (xa hoi)). hieu va cam luc van hanh kem cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ty) OR (sac ky)) nang ((x hoi) OR (xa hoi)). hieu va cam luc van hanh kem cua tre.
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) or (sac ky)) nang ((x hoi) or (xa hoi)). hieu va cam luc van hanh kem cua tre*.