Perhaps you should try some spelling variations:
dong thuoc » dung thuoc, dang thuoc, don thuoc
hanh dong » anh dong, ha dong
dich hoc » sinh hoc, hinh hoc, kinh hoc
tinh hoc » sinh hoc, tin hoc, hinh hoc
cuu toan » cuu hoan, cua toan, huu toan
toan hoc » toan khoa, van hoc, hoa hoc
hoc hanh » hoc nhanh, hoc thanh, hoc anh
thuoc ma » hoc ma, duoc ma
nhan dan » phan dau, gian dan, nhan tai
ma hoc » va hoc, ma hoa, mo hoc
hoc ca » hoc cao, hoc cua, hoc cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: chu ((dich hoc) or (tinh hoc)) tap, nghien cuu toan hoc hanh dong thuoc ma hoc ca nhan dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: chu ((dich hoc) OR (tinh hoc)) tap, nghien cuu toan hoc hanh dong thuoc ma hoc ca nhan dan.
• Adding a wildcard symbol may retrieve word variants: chu ((dich hoc) or (tinh hoc)) tap, nghien cuu toan hoc hanh dong thuoc ma hoc ca nhan dan*.