Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hoc thieu » hoc hien
trinh van » trinh han, trinh quan, trinh toan
trinh va » trinh vat, trinh ve, trinh vi
cong bai » cuong bai, cong hai, cung bai
bai toan » bai tap
toan ban » van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((hoc thieu) or (toc thieu)) xanh - hanh ((trinh va) OR (trinh van)) nhung cong bai toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((hoc thieu) OR (toc thieu)) xanh - hanh ((trinh va) OR (trinh van)) nhung cong bai toan ban.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((hoc thieu) or (toc thieu)) xanh - hanh ((trinh va) OR (trinh van)) nhung cong bai toan ban".
• Adding a wildcard symbol may retrieve word variants: ((hoc thieu) or (toc thieu)) xanh - hanh ((trinh va) OR (trinh van)) nhung cong bai toan ban*.