Perhaps you should try some spelling variations:
thanh doi » thanh loi, thanh moi, thanh hoai
su triet » su viet, su tien, ve triet
thanh do » thanh de, thanh pho, thanh hoa
dang xay » dang van, van xay
cac tuc » cac toc, cac tu, cac tac
vu sach » vu bach, su sach, vu khach
sach ty » sach y, sach tu, sach thu
nang xa » nang x, lang xa, nang ma
hieu va » lieu va, hieu qua
tuc va » thuc va, truc va, tuc xa

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

• Performing a fuzzy search may retrieve terms with similar spellings: vu sach ty ((nang xa) or (dang xay)) hoi. hieu va cac tuc va ((thanh doi) OR (thanh do)) su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: vu sach ty ((nang xa) OR (dang xay)) hoi. hieu va cac tuc va ((thanh doi) OR (thanh do)) su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "vu sach ty ((nang xa) or (dang xay)) hoi. hieu va cac tuc va ((thanh doi) OR (thanh do)) su triet".
• Adding a wildcard symbol may retrieve word variants: vu sach ty ((nang xa) or (dang xay)) hoi. hieu va cac tuc va ((thanh doi) OR (thanh do)) su triet*.