Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
va dinh » van dinh, va kinh, va tinh
ty nang » ky nang, ty xang, ty hang
nang xa » nang x, lang xa, nang ma
hieu ve » hieu va, hieu van
dinh vi » dinh ve, dinh viet, dinh tri
cac duc » cao duc, cac dac, cac nuoc
vi cua » vai cua, di cua
cua te » cua tu

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: ((te sach) OR (toc sach)) ty nang xa hoi. hieu ve ((cac duc) OR (cac du)) va dinh vi cua te~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((te sach) OR (toc sach)) ty nang xa hoi. hieu ve ((cac duc) or (cac du)) va dinh vi cua te~".
• Adding a wildcard symbol may retrieve word variants: ((te sach) OR (toc sach)) ty nang xa hoi. hieu ve ((cac duc) or (cac du)) va dinh vi cua te*.