Perhaps you should try some spelling variations:
nang mai » nang ma, nang tai, lang mai
hieu van » thien van, lieu va, hieu ve
te sach » toc sach
sach ky » sac ky, sach y, sach ty
mai hoi » mai khoi, dai hoi, lai hoi
hieu va » lieu va, hieu qua
xuc ban » duc ban, cuc ban, quoc ban
banh vi » ban vi, benh vi, banh chi
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: te sach ky nang mai hoi. ((hieu van) or (hieu va)) cam xuc ban ((banh vi) OR (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach ky nang mai hoi. ((hieu van) OR (hieu va)) cam xuc ban ((banh vi) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach ky nang mai hoi. ((hieu van) or (hieu va)) cam xuc ban ((banh vi) OR (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: te sach ky nang mai hoi. ((hieu van) or (hieu va)) cam xuc ban ((banh vi) OR (hanh vi)) cua tre*.