Perhaps you should try some spelling variations:
khanh hoa » thanh hoa, hang hoa
mach hoc » cach hoc, anh hoc, bac hoc
dich hoc » sinh hoc, hinh hoc, tinh hoc
cuu dong » cuu cong, cuu tong, cuu long
co khanh » co thanh, o khanh, co hanh
gian dan » gian lang
va gian » va gianh, van gian, va giai
hoc xa » hoc ma

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 (dich hoc)) tap, nghien cuu dong co khanh hoa hoc xa hoi va gian dan~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((mach hoc) OR (dich hoc)) tap, nghien cuu dong co khanh hoa hoc xa hoi va gian dan.
• Adding a wildcard symbol may retrieve word variants: tu ((mach hoc) or (dich hoc)) tap, nghien cuu dong co khanh hoa hoc xa hoi va gian dan*.