Perhaps you should try some spelling variations:
thanh vai » thanh van, thanh tai, thanh oai
thanh hai » thanh phan, thanh hoa, thanh san
te sach » toc sach
duc van » duc va, duc tan, duc manh
cau duc » cao duc, cau luc, chu duc
sach vu » sach va, sach tu, sach uu
hieu va » lieu va
nang xa » nang x, lang xa, nang ma
vu nang » vuc nang, va nang, vu dang
cua su » qua su

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

• Performing a fuzzy search may retrieve terms with similar spellings: te sach vu nang xa hoi. ((hieu va) OR (hieu qua)) cau duc van ((thanh vai) or (thanh hai)) cua su~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te sach vu nang xa hoi. ((hieu va) OR (hieu qua)) cau duc van ((thanh vai) OR (thanh hai)) cua su.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te sach vu nang xa hoi. ((hieu va) OR (hieu qua)) cau duc van ((thanh vai) or (thanh hai)) cua su".
• Adding a wildcard symbol may retrieve word variants: te sach vu nang xa hoi. ((hieu va) OR (hieu qua)) cau duc van ((thanh vai) or (thanh hai)) cua su*.