Perhaps you should try some spelling variations:
hieu lang » chieu sang, hieu quang, nhieu tang
cuong tap » luong tap, cong tac, luong tai
hoc hieu » hoc thieu, hoc hien, doc hieu
trinh va » trinh van, trinh vat, trinh ve
tran van » luan van
cong tap » cong tac, cong tan, tong tap
toan cao » toan ban, toan tap

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

• Performing a fuzzy search may retrieve terms with similar spellings: hoc hieu lang - canh ((trinh va) or (tran van)) dang ((cong tap) or (cuong tap)) toan cao~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hieu lang - canh ((trinh va) OR (tran van)) dang ((cong tap) OR (cuong tap)) toan cao.
• Adding a wildcard symbol may retrieve word variants: hoc hieu lang - canh ((trinh va) or (tran van)) dang ((cong tap) or (cuong tap)) toan cao*.