Perhaps you should try some spelling variations:
toc sach » doc sach, thuoc sach, nuoc sach
hoc sach » hoc sinh, hoc cac, hoc anh
va dinh » van dinh, va kinh, va tinh
va danh » va dan, va hanh, dia danh
cao luc » bao luc, cao duc, cao suc
ca tren » cau tren, cu tren, la tren
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
v nang » va nang, vu nang, van nang
va cao » va cac, va co, va dao
di ca » di cau, di cua, doi ca

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

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