Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
hien xanh » hien hanh, hien nhanh, chieu xanh
tranh van » tran van, trinh van, thanh van
tranh va » trang va, trinh va, thanh va
cong ban » cong bang, cong san, cong tan
ban toan » bai toan, ban than, van toan
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 hien xanh - hanh ((tranh va) OR (tranh van)) nhung cong ban toan cao~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc hien xanh - hanh ((tranh va) OR (tranh van)) nhung cong ban toan cao".
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - hanh ((tranh va) OR (tranh van)) nhung cong ban toan cao*.