Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach thi » sach thu, sach tai, sach thieu
van dinh » van minh, van dich, va dinh
cau tren » cu tren, dau tren, ca tren
thi nang » thi cong, ki nang, thi hanh
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
dinh di » dinh du, dinh vi, danh di
dam tu » nam tu, dam thuc
cam tu » cam thu, nam tu
tam tu » nam tu, tam thuc
di cau » da cau, diem cau

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 thi nang xa hoi. hieu va ((dam tu) OR (((cam tu) OR (tam tu)))) van dinh di cau tren~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach thi nang xa hoi. hieu va ((dam tu) or (((cam tu) OR (tam tu)))) van dinh di cau tren~".
• Adding a wildcard symbol may retrieve word variants: toc sach thi nang xa hoi. hieu va ((dam tu) or (((cam tu) OR (tam tu)))) van dinh di cau tren*.