Perhaps you should try some spelling variations:
qua thanh » quan thanh, cua thanh, qua than
qua tham » qua cham, qua than, quan pham
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
va hanh » van hanh, va thanh, va danh
cua tre » cua te, cuu tre, cua triet
de tai » de thi, te tai
ve cac » va cac, vien cac
soc va » hoc va, loc va, doc va
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: ((de tai) or (ve cac)) ky dang xa hoi. hieu ((qua tham) OR (qua thanh)) soc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((de tai) OR (ve cac)) ky dang xa hoi. hieu ((qua tham) OR (qua thanh)) soc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((de tai) or (ve cac)) ky dang xa hoi. hieu ((qua tham) OR (qua thanh)) soc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: ((de tai) or (ve cac)) ky dang xa hoi. hieu ((qua tham) OR (qua thanh)) soc va hanh vi cua tre*.