Perhaps you should try some spelling variations:
khoa hoi » khoan hoi, khoa hoc, khoa doi
van hanh » van thanh, ban hanh, van ban
te sach » toc sach
hoa hoi » hoa hoc, hoa doi, hoc hoi
hieu le » hieu ve, hieu he, hieu ly
van anh » van thanh, tuan anh, van minh
su tien » su kien, su hien, tu tieng
y lang » o lang, _ lang, tay lang
le nam » ly nam, he nam, le na
vai su » va su, van su, lai su

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach y lang ((hoa hoi) or (khoa hoi)). hieu le nam thu ((van hanh) OR (van anh)) vai su tien~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach y lang ((hoa hoi) OR (khoa hoi)). hieu le nam thu ((van hanh) OR (van anh)) vai su tien.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach y lang ((hoa hoi) or (khoa hoi)). hieu le nam thu ((van hanh) OR (van anh)) vai su tien".
• Adding a wildcard symbol may retrieve word variants: te sach y lang ((hoa hoi) or (khoa hoi)). hieu le nam thu ((van hanh) OR (van anh)) vai su tien*.