Perhaps you should try some spelling variations:
khoa dang » khoa dung, hoa dan, hoa dong
tai khoa » da khoa, noi khoa
chat xuc » chat huu, cam xuc, chao xu
va chat » van chat, va phat, cao chat
xuc van » duc van, luc van, vuc van
cua tre » cua te, cuu tre, cua triet
ha hoi » hoa hoi, ha noi, va hoi
anh vi » anh va, anh ve, anh vu

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu tai khoa dang ((ha hoi) or (xa hoi)). lieu va chat xuc van ((anh vi) OR (hanh vi)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu tai khoa dang ((ha hoi) OR (xa hoi)). lieu va chat xuc van ((anh vi) OR (hanh vi)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu tai khoa dang ((ha hoi) or (xa hoi)). lieu va chat xuc van ((anh vi) OR (hanh vi)) cua tre".
• Adding a wildcard symbol may retrieve word variants: tu tai khoa dang ((ha hoi) or (xa hoi)). lieu va chat xuc van ((anh vi) OR (hanh vi)) cua tre*.