Perhaps you should try some spelling variations:
mai khoi » mai khoa, tai khoa, cac khoi
hieu van » hieu va, thien van, lieu va
van hanh » van thanh, ban hanh, van anh
cau treo » cau theo, cau tren, cau triet
dau tren » dau tien, dat tren, dau tieng
van hai » van ha, van chat, van phan
hai luc » hai cuc, khai luoc, nhan luc
luc van » luoc van, luu van, duc van
su sac » su sach, su cac, su xac
sac ky » cac ky, sai ky

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sac ky nang ((ma hoa) or (mai khoi)). hieu van hai luc van hanh vi ((cau treo) or (dau tren))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang ((ma hoa) OR (mai khoi)). hieu van hai luc van hanh vi ((cau treo) OR (dau tren)).
• Adding a wildcard symbol may retrieve word variants: su sac ky nang ((ma hoa) or (mai khoi)). hieu van hai luc van hanh vi ((cau treo) or (dau tren))*.