Perhaps you should try some spelling variations:
hoc nganh » hoc nhanh
nang thai » dang thai, lang thai, nang hai
nganh ky » nganh y, nganh xay, hanh ky
nang tai » hang tai, tang tai, sang tai
hieu van » hieu va, thien van, lieu va
lang van » dang van, tang van, hoang van
hieu ve » hieu va
van hoi » van hoa, van hoc, van hoe
cac duc » cac du, cao duc, cac dac
ky lang » ky nang, ky dang, ky tang
cua tre » cua te, cuu tre, cua triet

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 ky lang van hoi. ((hieu ve) OR (hieu van)) cac duc va ((nang thai) or (nang tai)) cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc nganh ky lang van hoi. ((hieu ve) OR (hieu van)) cac duc va ((nang thai) OR (nang tai)) cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc nganh ky lang van hoi. ((hieu ve) OR (hieu van)) cac duc va ((nang thai) or (nang tai)) cua tre".
• Adding a wildcard symbol may retrieve word variants: hoc nganh ky lang van hoi. ((hieu ve) OR (hieu van)) cac duc va ((nang thai) or (nang tai)) cua tre*.