Perhaps you should try some spelling variations:
cua viet » ca viet, hoa viet, cua vat
lang van » dang van, tang van, hoang van
sach ky » sac ky, sach y, sach ty
su sach » so sach, vu sach
lang xa » lang ha, dang xay
hieu ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam
tuc va » thuc va, truc va, duc va
vi cua » vai cua, di cua

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 ((lang xa) OR (lang van)) hoi. hieu ve cam ((tuc va) or (tuc xa)) hanh vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky ((lang xa) OR (lang van)) hoi. hieu ve cam ((tuc va) OR (tuc xa)) hanh vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky ((lang xa) OR (lang van)) hoi. hieu ve cam ((tuc va) or (tuc xa)) hanh vi cua viet".
• Adding a wildcard symbol may retrieve word variants: su sach ky ((lang xa) OR (lang van)) hoi. hieu ve cam ((tuc va) or (tuc xa)) hanh vi cua viet*.