Perhaps you should try some spelling variations:
nang hoc » nang doc, nang luc, dong hoc
hanh tri » thanh tri, hanh tai, hanh trinh
tu sach » thu sach, su sach, te sach
hieu ve » hieu va, hieu van
xuc ban » duc ban, cuc ban, quoc ban
duc van » duc va, duc tan, duc manh
cua tre » cua te, cuu tre, cua triet
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: tu sach y ((nang cao) or (nang hoc)) hai. hieu ve cac ((xuc ban) or (duc van)) hanh tri cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach y ((nang cao) OR (nang hoc)) hai. hieu ve cac ((xuc ban) OR (duc van)) hanh tri cua tre.
• Adding a wildcard symbol may retrieve word variants: tu sach y ((nang cao) or (nang hoc)) hai. hieu ve cac ((xuc ban) or (duc van)) hanh tri cua tre*.