Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
hieu van » hieu va, thien van, lieu va
tan hanh » tan thanh, tang hanh, toan hanh
hanh lam » thanh lap, hanh kem, hanh va
tu sach » thu sach, su sach, te sach
mang xa » lang xa, mang may, dang xay
van cam » van nam, van lam, van cau
cam duc » cam xuc, cao duc, pham duc
lam cua » nam cua, lam chat
cua tre » cua te, cuu tre, cua triet

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu sach thu ((mang xa) or (nang x)) hoi. hieu van cam duc tan hanh lam cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach thu ((mang xa) OR (nang x)) hoi. hieu van cam duc tan hanh lam cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach thu ((mang xa) or (nang x)) hoi. hieu van cam duc tan hanh lam cua tre*.