Perhaps you should try some spelling variations:
hoc khoi » hoc khoa, hoc hoa, hoc noi
cua viet » ca viet, hoa viet, cua dieu
van hanh » van thanh, ban hanh, van anh
hieu ve » hieu va, hieu van
cac tuc » cac toc, cac tu, cac tac
hanh de » hanh ve, hanh kem
tuc van » thuc van, truc van, tuc va
su sac » su sach, su cac, su xac
ve cac » va cac, vien cac
sac ky » cac ky, sai ky
ho hoi » hoc hoi, hoa hoi, hoi hoi

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 ((ho hoi) or (hoc khoi)). hieu ve cac tuc van hanh de ((cua viet) OR (cua vat))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sac ky nang ((ho hoi) OR (hoc khoi)). hieu ve cac tuc van hanh de ((cua viet) OR (cua vat))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sac ky nang ((ho hoi) or (hoc khoi)). hieu ve cac tuc van hanh de ((cua viet) OR (cua vat))*".