Perhaps you should try some spelling variations:
doc sach » toc sach, nuoc sach, dac sac
hoc sach » hoc sinh, hoc cac, hoc anh
va hanh » van hanh, va thanh, va danh
thuc va » thuc vat, thuc dan, thuc day
nang xa » nang x, lang xa, nang ma
va cau » van cau, va dau, va cao
v nang » va nang, vu nang, van nang
vi cua » vai cua, di cua
cua tu » cua tuc, cua su, cua cu

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

• Performing a fuzzy search may retrieve terms with similar spellings: ((doc sach) or (hoc sach)) v nang xa hoi. hieu ((va cau) or (va cac)) thuc va hanh vi cua tu~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((doc sach) OR (hoc sach)) v nang xa hoi. hieu ((va cau) OR (va cac)) thuc va hanh vi cua tu.
• Adding a wildcard symbol may retrieve word variants: ((doc sach) or (hoc sach)) v nang xa hoi. hieu ((va cau) or (va cac)) thuc va hanh vi cua tu*.