Perhaps you should try some spelling variations:
hoc nganh » hoc nhanh
lang van » tang van, hoang van, giang van
dang van » hoang van, hang va
hanh hai » thanh hai, nhanh hai, hang hai
va triet » va thiet, va trien, ve triet
hieu ve » hieu va, hieu van
cac dac » cac dan, cac dai, cac bac
va hanh » van hanh, va thanh, va danh
ve cac » va cac, vien cac
dac va » duc va, day va, dat va
hai va » hai van, thai va, hoi va

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc nganh y ((lang van) or (dang van)) hoi. hieu ve cac dac va hanh hai va triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc nganh y ((lang van) OR (dang van)) hoi. hieu ve cac dac va hanh hai va triet.
• Adding a wildcard symbol may retrieve word variants: hoc nganh y ((lang van) or (dang van)) hoi. hieu ve cac dac va hanh hai va triet*.