Perhaps you should try some spelling variations:
cua viet » ca viet, cua vat, cua dieu
sach thu » sach thue, sach thieu, sach tham
dang xay » dang van, van xay
hanh lai » hanh lam, hanh tai, thanh lap
van hanh » van thanh, ban hanh, van anh
duc van » duc va, duc tan, duc manh
hieu ve » hieu va, hieu van
ve pham » vi pham, v pham, ve phan
sach ty » sach y, sach tu, xach tay
xay hoi » xa hoi, tay hoi, cay phoi

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