Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach va » sach xa, sach ha, sach dao
va danh » va dinh, va dan, dia danh
va hanh » van hanh, va thanh, ban hanh
cua tre » cua te, cuu tre, cua triet
cac luc » cau luc, cac nuoc, cac cuoc
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
va nang » van nang, da nang, cam nang
de cua » le cua, te cua, dieu cua

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 va nang xa hoi. hieu va ((cac luc) or (coc luc)) ((va hanh) OR (va danh)) de cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach va nang xa hoi. hieu va ((cac luc) OR (coc luc)) ((va hanh) OR (va danh)) de cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach va nang xa hoi. hieu va ((cac luc) or (coc luc)) ((va hanh) OR (va danh)) de cua tre".
• Adding a wildcard symbol may retrieve word variants: toc sach va nang xa hoi. hieu va ((cac luc) or (coc luc)) ((va hanh) OR (va danh)) de cua tre*.