Perhaps you should try some spelling variations:
tinh voi » trinh voi, tinh doi, binh voi
hieu van » hieu va, thien van, lieu va
tu sach » thu sach, su sach, tu cach
cam cuc » cam xuc, cham cuu, pham cuc
tinh vi » trinh vi, tinh va, dinh vi
cuc ban » cua ban, cac ban, cuu ban
van cam » van nam, van lam, van cau
tang xa » trang xa, tang ma, lang xa
ky tang » ky nang, ky dang, kho tang
te sach » toc sach
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) or (te sach)) ky tang xa hoi. hieu van cam cuc ban ((tinh vi) OR (tinh voi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky tang xa hoi. hieu van cam cuc ban ((tinh vi) OR (tinh voi)) cua tre*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) ky tang xa hoi. hieu van cam cuc ban ((tinh vi) OR (tinh voi)) cua tre*".