Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
thanh vi » hanh vi, thanh va, thanh ve
quoc lan » nuoc luan, quoc quan, quoc danh
quoc ban » quoc bao, quoc quan, quoc binh
hieu va » lieu va, hieu qua
nang xa » nang x, lang xa, nang ma
sach v » sach va, sach 2, sach vay
va cam » va cham, va cac, va cao
vi su » va su, ve su, ki su

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

• Performing a fuzzy search may retrieve terms with similar spellings: tu ((sach v) or (sach y)) nang xa hoi. hieu va cam ((quoc ban) OR (quoc lan)) thanh vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu ((sach v) OR (sach y)) nang xa hoi. hieu va cam ((quoc ban) OR (quoc lan)) thanh vi su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu ((sach v) or (sach y)) nang xa hoi. hieu va cam ((quoc ban) OR (quoc lan)) thanh vi su triet".
• Adding a wildcard symbol may retrieve word variants: tu ((sach v) or (sach y)) nang xa hoi. hieu va cam ((quoc ban) OR (quoc lan)) thanh vi su triet*.