Perhaps you should try some spelling variations:
nghien ha » nghiep ha, nghiem hoa, nghiep nha
phan khoa » pham khoa, nhan khoa, phan hoa
mach hoc » dich hoc, anh hoc, bac hoc
cach hoc » cach thuc, cach thoi, dich hoc
dong hoa » dong hoc, dong co
hoa phan » hoa dan, co phan
khoa hoc » hoa hoc
dan chan » dan gian, dan ca, van chat
ha dong » hoat dong, van dong
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) OR (cach hoc)) tap, nghien ha dong hoa phan khoa hoc va hoc dan chan va~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((mach hoc) OR (cach hoc)) tap, nghien ha dong hoa phan khoa hoc va hoc dan chan va".
• Adding a wildcard symbol may retrieve word variants: tu ((mach hoc) OR (cach hoc)) tap, nghien ha dong hoa phan khoa hoc va hoc dan chan va*.