Perhaps you should try some spelling variations:
cau tren » cu tren, dau tren, ca tren
hieu van » hieu va, thien van, lieu va
kho tang » cao tang
van hanh » van thanh, ban hanh, van anh
cuu tre » cua tre, cau treo
duc van » duc va, duc tan, duc manh
cam duc » cam xuc, cao duc, pham duc
can kho » can ho, can tho, can who
hieu ve » hieu va
tang xa » trang xa, tang ma, lang xa
tu can » tu ban, tu cac, thu canh

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu can kho tang xa hoi. ((hieu ve) or (hieu van)) cam duc van hanh vi ((cuu tre) OR (cau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu can kho tang xa hoi. ((hieu ve) OR (hieu van)) cam duc van hanh vi ((cuu tre) OR (cau tren))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu can kho tang xa hoi. ((hieu ve) or (hieu van)) cam duc van hanh vi ((cuu tre) OR (cau tren))*".