Perhaps you should try some spelling variations:
toc giay » toc tay, tac gia, hoc giao
su sach » so sach, vu sach
so giao » so giai, hoc giao
sach ky » sac ky, sach y, sach ty
va cham » va chat, va tham
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
ky lang » ky nang, ky dang, ky tang
vi cu » vi su, vi xu
vi du » vi dum, va du, ve du

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 hoi. hieu va cham ((toc giay) or (so giao)) thanh ((vi cu) OR (vi du)) tren~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ky lang xa hoi. hieu va cham ((toc giay) OR (so giao)) thanh ((vi cu) OR (vi du)) tren.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ky lang xa hoi. hieu va cham ((toc giay) or (so giao)) thanh ((vi cu) OR (vi du)) tren".
• Adding a wildcard symbol may retrieve word variants: su sach ky lang xa hoi. hieu va cham ((toc giay) or (so giao)) thanh ((vi cu) OR (vi du)) tren*.