Perhaps you should try some spelling variations:
sach thu » sach thue, sach thieu, sach tham
hieu van » hieu va, thien van, lieu va
van pham » san pham, van phan, van phat
tan hanh » tan thanh, tang hanh, toan hanh
chua tre » chua tri, cua tre, chua trieu
su sach » so sach, vu sach
nang xa » lang xa, nang ma, mang xa
hanh va » hang va, hanh vi
va chua » vua chua, ca chua, va chu

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 thu ((nang xa) or (nang x)) hoi. hieu van pham duc tan hanh va chua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach thu ((nang xa) OR (nang x)) hoi. hieu van pham duc tan hanh va chua tre.
• Adding a wildcard symbol may retrieve word variants: su sach thu ((nang xa) or (nang x)) hoi. hieu van pham duc tan hanh va chua tre*.