Perhaps you should try some spelling variations:
mach hoc » cach hoc, dich hoc, anh hoc
hoi thao » hoi trac, hoi nhap, thi thao
hoi khoa » hoc khoa, noi khoa, tai khoa
sach dao » lanh dao
su mach » su sach
hoc hoa » hoc khoa
vu khac » vu kham, vu khanh, bui khac
vu sach » vu bach, su sach, vu khach
dao hoa » dao hoan, do hoa, dao ho

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( su mach hoc hoa ) or ((( vu khac ((hoi thao) or (hoi khoa)) ) or ( vu sach dao hoa ))))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( su mach hoc hoa ) OR ((( vu khac ((hoi thao) OR (hoi khoa)) ) OR ( vu sach dao hoa )))).
• Adding a wildcard symbol may retrieve word variants: (( su mach hoc hoa ) or ((( vu khac ((hoi thao) or (hoi khoa)) ) or ( vu sach dao hoa ))))*.