Perhaps you should try some spelling variations:
nghien chua » nghien cuu, nghiep cua, nghiem thuat
mach hoc » cach hoc, dich hoc, anh hoc
dong hoa » dong co
dong hoc » dong co, dong luc
phan hoa » phan loai, phan phoi, phan hong
dan chan » dan gian, dan ca, van chat
tu mach » tu cach, tu manh, tu hach
chan va » chuan va, nhan va, chat va
va hoc » van hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu mach hoc tap, nghien chua ((dong hoa) OR (dong hoc)) phan hoa hoc va hoc dan chan va~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu mach hoc tap, nghien chua ((dong hoa) OR (dong hoc)) phan hoa hoc va hoc dan chan va".
• Adding a wildcard symbol may retrieve word variants: tu mach hoc tap, nghien chua ((dong hoa) OR (dong hoc)) phan hoa hoc va hoc dan chan va*.