Perhaps you should try some spelling variations:
nhanh thanh » phan thanh, nhanh tinh
hanh thai » nhanh thai, hinh thai, hanh tai
cac luc » cau luc, coc luc, cac nuoc
luc van » luoc van, luu van, duc van
cua tre » cua te, cuu tre, cua triet
sach ky » sac ky, sach ty, sach kem
hieu ve » hieu va, hieu van
nang o » nang co, nang ho, nang ro
ve cac » va cac, vien cac
o hoc » co hoc, mo hoc, so hoc

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