Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
kem cua » em cua, keo cua, diem cua
luc van » luoc van, luu van, duc van
cac luc » cau luc, coc luc, cac nuoc
hieu ve » hieu va, hieu van
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach ty, sach kem
nang xa » lang xa, nang ma, mang xa
ve cac » va cac, vien cac

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 ky) or (sach y)) ((nang xa) or (nang x)) hoi. hieu ve cac luc van hanh kem cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ky) OR (sach y)) ((nang xa) OR (nang x)) hoi. hieu ve cac luc van hanh kem cua tre.
• Adding a wildcard symbol may retrieve word variants: te ((sach ky) or (sach y)) ((nang xa) or (nang x)) hoi. hieu ve cac luc van hanh kem cua tre*.