Perhaps you should try some spelling variations:
hien xanh » hien hanh, hien nhanh, chieu xanh
dung cong » dung trong
cong vang » cong lang, cong quang, cong ngang
khoan cam » khoa cam, khoan va, phan cam
anh dang » anh dong, anh dung, anh bang
dang cua » dung cua, dong cua, mang cua
cua dung » cua dang, cua dong, qua dung
than cap » khan cap, thanh lap, thanh cac

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 - anh dang cua dung cong vang ((than cap) or (khoan cam))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: hoc hien xanh - anh dang cua dung cong vang ((than cap) OR (khoan cam)).
• Adding a wildcard symbol may retrieve word variants: hoc hien xanh - anh dang cua dung cong vang ((than cap) or (khoan cam))*.