Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
tuan hoc » luan hoc, than hoc, quang hoc
toan hoc » toan khoa, van hoc, hoa 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, cuu tre, luy tre
te sac » te sach, te san
te cac » tu cac, ve cac, te cao
vi luu » vi lua

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