Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
vu dang » su dang, vu quang, cua dang
dang xa » dang xay, lang xa, dang ha
hieu va » hieu qua
sach vu » sach va, sach tu, sach uu
cam loc » cam lo
hanh ve » hanh vi, hanh va
loc va » hoc va, luc va
cua te » cua tu

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

• Performing a fuzzy search may retrieve terms with similar spellings: toc sach vu dang xa hoi. ((hieu va) or (lieu va)) cam loc va ((hanh ve) or (hanh kem)) cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach vu dang xa hoi. ((hieu va) OR (lieu va)) cam loc va ((hanh ve) OR (hanh kem)) cua te.
• Adding a wildcard symbol may retrieve word variants: toc sach vu dang xa hoi. ((hieu va) or (lieu va)) cam loc va ((hanh ve) or (hanh kem)) cua te*.