Perhaps you should try some spelling variations:
nhung cong » dung cong, thong cong, hang cong
lieu tinh » trieu tinh, diep tinh, bien tinh
hanh mang » nhanh mang, hanh trang, nhanh lang
cong tac » cong ty
tac tren » rac tren, tai tren, tap tren
tren dat » tren dia, tren may
mang va » mang vua, hang va, bang va

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

• Performing a fuzzy search may retrieve terms with similar spellings: theo ((dieu hanh) or (lieu tinh)) - hanh mang va nhung cong tac tren dat~.
• If you are trying to use Boolean operators, they must be ALL CAPS: theo ((dieu hanh) OR (lieu tinh)) - hanh mang va nhung cong tac tren dat.
• Adding a wildcard symbol may retrieve word variants: theo ((dieu hanh) or (lieu tinh)) - hanh mang va nhung cong tac tren dat*.