Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
hai cua » thai cua, dai cua, hoi cua
vai cua » dai cua, lai cua, bai cua
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
ky canh » ky cach, ky danh, ky hanh
cac tu » cac thu, cach tu, cac du
tu van » tu va
ky anh » ky danh, ly anh, ty anh
ve cac » va cac, vien cac

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

• Performing a fuzzy search may retrieve terms with similar spellings: su sach ((ky canh) OR (ky anh)) xa hoi. hieu ve cac tu van hanh ((vai cua) or (hai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((ky canh) OR (ky anh)) xa hoi. hieu ve cac tu van hanh ((vai cua) OR (hai cua)) triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((ky canh) OR (ky anh)) xa hoi. hieu ve cac tu van hanh ((vai cua) or (hai cua)) triet".
• Adding a wildcard symbol may retrieve word variants: su sach ((ky canh) OR (ky anh)) xa hoi. hieu ve cac tu van hanh ((vai cua) or (hai cua)) triet*.