Perhaps you should try some spelling variations:
van khanh » van thanh, van hanh, van anh
nien cau » nien dau, khien cau, nhieu cau
hien cau » khien cau, thien cau, hien cac
truc van » truc va, thuc van, truc ban
khanh di » khanh bui, khanh duy, thanh doi
su triet » su viet, su tien, ve triet
sach v » sach va, sach 2, sach vay
x hoi » xa hoi, o hoi, x ho
di su » doi su, ki su, da su

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

• Performing a fuzzy search may retrieve terms with similar spellings: su ((sach v) or (sach y)) nang x hoi. thieu ((nien cau) OR (hien cau)) truc van khanh di su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su ((sach v) OR (sach y)) nang x hoi. thieu ((nien cau) OR (hien cau)) truc van khanh di su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su ((sach v) or (sach y)) nang x hoi. thieu ((nien cau) OR (hien cau)) truc van khanh di su triet".
• Adding a wildcard symbol may retrieve word variants: su ((sach v) or (sach y)) nang x hoi. thieu ((nien cau) OR (hien cau)) truc van khanh di su triet*.