Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
cam duc » cam xuc, cao duc, pham duc
hai cua » thai cua, dai cua, hoi cua
lai cua » dai cua, lai chau, thai cua
duc van » duc va, duc tan, duc manh
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
hieu ve » hieu va, hieu van
xay hoi » tay hoi, cay phoi, gay thoi
ty dang » ty xang, ky dang, ty hang
ve cam » ve cham, ve cac, va cam

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

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