Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
dieu cua » dieu tra
dan dieu » dang dieu, doan dieu, da dieu
vu nang » vuc nang, va nang, vu dang
nang xa » nang x, lang xa, nang ma
hieu va » hieu qua
sach vu » sach va, sach tu, sach uu
cam luc » cam xuc, cau luc
va dan » ca dan, va dao, va dau
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 nang xa hoi. ((hieu va) or (lieu va)) ((cam luc) or (chau au)) va dan dieu cua te~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach vu nang xa hoi. ((hieu va) OR (lieu va)) ((cam luc) OR (chau au)) va dan dieu cua te.
• Adding a wildcard symbol may retrieve word variants: toc sach vu nang xa hoi. ((hieu va) or (lieu va)) ((cam luc) or (chau au)) va dan dieu cua te*.