Perhaps you should try some spelling variations:
sach dao » lanh dao
va hanh » van hanh, va thanh, va danh
cau tuc » cau truc, cau tu, cau luc
hieu va » lieu va, hieu qua
lang xa » lang ha, dang xay, lang van
cua tre » cua te, cuu tre, cua triet
sach va » sach xa, sach ha, sach nha
sach v » sach y, sach 2, sach vay
va cau » van cau, va cac, va dau
tuc va » thuc va, truc va, tuc xa
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: toc ((sach v) or (((sach va) OR (sach dao)))) lang xa hoi. hieu va cau tuc va hanh vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc ((sach v) OR (((sach va) OR (sach dao)))) lang xa hoi. hieu va cau tuc va hanh vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc ((sach v) or (((sach va) OR (sach dao)))) lang xa hoi. hieu va cau tuc va hanh vi cua tre".
• Adding a wildcard symbol may retrieve word variants: toc ((sach v) or (((sach va) OR (sach dao)))) lang xa hoi. hieu va cau tuc va hanh vi cua tre*.