Perhaps you should try some spelling variations:
toc sach » hoc sach, doc sach, thuoc sach
sach vu » sach va, sach tu, sach uu
vu nang » vuc nang, va nang, vu dang
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
cac luc » cau luc, coc luc, cac nuoc
luc gia » luoc gia, duc gia, quoc gia
di cua » doi cua, de cua, do cua

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 cac luc gia thanh ((di cua) OR (dai cua)) tre~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach vu nang xa hoi. hieu va cac luc gia thanh ((di cua) OR (dai cua)) tre".
• Adding a wildcard symbol may retrieve word variants: toc sach vu nang xa hoi. hieu va cac luc gia thanh ((di cua) OR (dai cua)) tre*.