Perhaps you should try some spelling variations:
vien nganh » vien thanh
tranh chua » tranh cua, trinh chuan, tranh chap
cong trong » cong thuong, duong trong, cong trinh
hieu xanh » chieu xanh, hieu manh, hieu nganh
tang chua » tang cua, tang ha, tang khu
trong san » trong cac, cong san, dong san
san toan » van toan, dan toan, manh toan
toan ban » van ban

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

• Performing a fuzzy search may retrieve terms with similar spellings: doc ((hieu xanh) or (vien nganh)) - hanh ((tang chua) or (tranh chua)) cong trong san toan ban~.
• If you are trying to use Boolean operators, they must be ALL CAPS: doc ((hieu xanh) OR (vien nganh)) - hanh ((tang chua) OR (tranh chua)) cong trong san toan ban.
• Adding a wildcard symbol may retrieve word variants: doc ((hieu xanh) or (vien nganh)) - hanh ((tang chua) or (tranh chua)) cong trong san toan ban*.