Perhaps you should try some spelling variations:
cham doc » cham soc, chat doc, pham duc
chau doc » chat doc, cau do, phau hoc
cuu tre » cau tren, cau treo
ky tang » ky nang, ky dang, kho tang
tang xa » trang xa, tang ma, lang xa
hieu ve » hieu va, hieu van
cua tre » cua te, cua triet, dua tren
dan vi » doan vi, don vi, dan va
tu san » thu san, tu ban, tu can
va dan » ca dan, va dao, va dau
san ky » sang ky, van ky, dan ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu san ky tang xa hoi. hieu ve ((cham doc) or (chau doc)) va dan vi ((cua tre) or (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu san ky tang xa hoi. hieu ve ((cham doc) OR (chau doc)) va dan vi ((cua tre) OR (cuu tre)).
• Adding a wildcard symbol may retrieve word variants: tu san ky tang xa hoi. hieu ve ((cham doc) or (chau doc)) va dan vi ((cua tre) or (cuu tre))*.