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
thi nang » thi cong, ki nang, thi hanh
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
dam tu » nam tu, cam tu, dam thuc
tam tu » nam tu, cam tu, tam thuc
di cau » diem cau
da cau » dat cau, va 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 (tam tu)) van dinh ((di cau) OR (da 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 (tam tu)) van dinh ((di cau) OR (da cau)) tren~".
• Adding a wildcard symbol may retrieve word variants: toc sach thi nang xa hoi. hieu va ((dam tu) or (tam tu)) van dinh ((di cau) OR (da cau)) tren*.