Perhaps you should try some spelling variations:
trinh dan » trinh han, trinh san, trinh da
dan hoang » dang hoang, van hoang, quan hoang
hoang van » hang va
tinh dung » trinh dung, tin dung, tinh huong
hieu suat » hieu luat, hieu qua
van kien » van tien, van hien, van chien
kien hoa » dien hoa, tien hoa, kien ha
van hieu » cao hieu
nam van » nam dan, nam va, pham van
quang » quan

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( trinh dan hoang van kien hoa ) or ( ((tinh dung) or (tinh quang)) nam van hieu suat ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( trinh dan hoang van kien hoa ) OR ( ((tinh dung) OR (tinh quang)) nam van hieu suat )).
• Adding a wildcard symbol may retrieve word variants: (( trinh dan hoang van kien hoa ) or ( ((tinh dung) or (tinh quang)) nam van hieu suat ))*.