Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
vu sach » vu bach, su sach, vu khach
tang xa » trang xa, tang ma, lang xa
cac tuc » cac tu, cac tac, cac nuoc
cac toc » cac toi, cac nuoc, cac thoi
va tinh » may tinh
tinh vi » trinh vi, tinh voi, tinh va
cua tre » cua te, cuu tre, cua triet
y tang » ky tang, 6 tang, 7 tang
vi cua » vai cua, di cua

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach y tang xa hoi. hieu van ((cac tuc) or (cac toc)) va tinh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach y tang xa hoi. hieu van ((cac tuc) OR (cac toc)) va tinh vi cua tre.
• Adding a wildcard symbol may retrieve word variants: vu sach y tang xa hoi. hieu van ((cac tuc) or (cac toc)) va tinh vi cua tre*.