Perhaps you should try some spelling variations:
cong thuong » hang thuong
thuong toan » truong toan, thuong han, phong toan
chieu xanh » chieu sach, chieu sang, chieu tinh
nhung cong » dung cong, thong cong, hang cong
hoc chieu » hoc thieu, ho chieu, hoc hien
trinh vat » trinh van, trinh luat, sinh vat
trinh va » trinh van, trinh ve, trinh vi
toan cau » 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 chieu xanh - hanh ((trinh va) or (trinh vat)) nhung cong thuong toan cau~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc chieu xanh - hanh ((trinh va) OR (trinh vat)) nhung cong thuong toan cau*.