Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
van hanh » van thanh, ban hanh, van anh
vu sach » vu bach, su sach, vu khach
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
su viet » so viet
ve bac » ve bao, ve cac, ve ban
bac so » bac son, bac si, bac bo
so van » su van, vo van
x hoi » xa hoi, o hoi, 5 hoi

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ky nang ((x hoi) OR (x ho)). hieu ve bac so van hanh vi ((cua triet) or (su viet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ky nang ((x hoi) OR (x ho)). hieu ve bac so van hanh vi ((cua triet) OR (su viet))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ky nang ((x hoi) OR (x ho)). hieu ve bac so van hanh vi ((cua triet) or (su viet))*".