Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
van tuan » van quan, van ban, anh tuan
tuan hoc » toan hoc, luan hoc, than hoc
ky dang » ky nang, ky danh
dang xa » dang xay, lang xa, dang ha
va hanh » van hanh, va thanh, va danh
luu tre » luu tru, luy tre
cuu tre » cua tre, cau tren, cau treo
te sac » te sach, te cac, te san

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((te sac) or (tu cac)) ky dang xa hoi. hieu van tuan hoc va hanh vi ((luu tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((te sac) OR (tu cac)) ky dang xa hoi. hieu van tuan hoc va hanh vi ((luu tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sac) or (tu cac)) ky dang xa hoi. hieu van tuan hoc va hanh vi ((luu tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: ((te sac) or (tu cac)) ky dang xa hoi. hieu van tuan hoc va hanh vi ((luu tre) OR (cuu tre))*.