Perhaps you should try some spelling variations:
nang doc » nang luc
hanh vai » hanh va, hanh tai, hanh van
su sach » so sach, vu sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
nang co » nang cao, nang noi, nang hoc
cua tre » cua te, cuu tre, cua triet
ve cam » ve cham, ve cac, va cam
xuc va » duc va, tuc va, luc va

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 ty ((nang co) or (nang doc)) hoi. hieu ve cam xuc va ((hanh vai) OR (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ty ((nang co) OR (nang doc)) hoi. hieu ve cam xuc va ((hanh vai) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ty ((nang co) or (nang doc)) hoi. hieu ve cam xuc va ((hanh vai) OR (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: su sach ty ((nang co) or (nang doc)) hoi. hieu ve cam xuc va ((hanh vai) OR (hanh vi)) cua tre*.