Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
doc diep » duoc dien, ngoc diep, dac diem
cong van » cong vang, cong san, song van
van toan » van tuan, van tan, van thanh
toan cau » toan cao, toan ban, toan tap
tung ve » dung ve, tung va, trung va
tung le » tuong le, tang le, dung le

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc diep tinh - thanh ((tung ve) OR (tung le)) nhung cong van toan cau~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "doc diep tinh - thanh ((tung ve) OR (tung le)) nhung cong van toan cau".
• Adding a wildcard symbol may retrieve word variants: doc diep tinh - thanh ((tung ve) OR (tung le)) nhung cong van toan cau*.