Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dang xay » dang van, van xay
ve triet » va trien, su triet
lang xa » lang ha, lang van
sach ky » sac ky, sach y, sach ty
hieu ve » hieu va, hieu van
ve cam » ve cham, ve cac, va cam
xuc va » duc va, luc va, xac va
tuc va » thuc va, truc va, tuc xa
kem ve » ke ve

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

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