Perhaps you should try some spelling variations:
toan khoan » toan khoa, toan phan, toan hoat
tuan dung » tuan duong, tran dung, tan dung
dung cong » dung trong
cong toan » cong tan, cong hoan, cong tuan
khoan cap » khoan cam, khan cap, khoa cap
cot lieu » co lieu, vat lieu, so lieu
ho lieu » so lieu, co lieu, ho kieu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((ho lieu) or (cot lieu)) tinh - ((thanh tung) OR (thanh cong)) tuan dung cong toan khoan cap~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((ho lieu) OR (cot lieu)) tinh - ((thanh tung) OR (thanh cong)) tuan dung cong toan khoan cap.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((ho lieu) or (cot lieu)) tinh - ((thanh tung) OR (thanh cong)) tuan dung cong toan khoan cap".
• Adding a wildcard symbol may retrieve word variants: ((ho lieu) or (cot lieu)) tinh - ((thanh tung) OR (thanh cong)) tuan dung cong toan khoan cap*.