Perhaps you should try some spelling variations:
hieu van » hieu va, thien van, lieu va
thai hoc » dai hoc, bai hoc, thai do
ky lang » ky nang, ky dang, ky tang
lang xa » lang ha, dang xay, lang van
hoi hoc » hoa hoc, khoa hoc, hoi chuc
va hanh » van hanh, va thanh, va danh
te cac » tu cac, ve cac, te cao
vi cua » vai cua
di cua » dai cua, doi cua, de cua

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

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