Perhaps you should try some spelling variations:
thieu nien » thien nhien
van khang » van khanh, van thanh, van quang
hieu vien » hieu hien, hieu viec, hieu tieng
su triet » su viet, su tien, ve triet
khang di » hang di, khang vi, khang voi
truc van » truc va, thuc van, truc ban
dai truc » dai thuc, doan truc, dai trung
su sach » so sach, vu sach
vu nang » vuc nang, va nang, vu dang
v nang » va nang, van nang, voi nang
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 nang) OR (vu nang)) x hoi. ((hieu vien) or (thieu nien)) dai truc van khang di su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((v nang) OR (vu nang)) x hoi. ((hieu vien) OR (thieu nien)) dai truc van khang di su triet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((v nang) OR (vu nang)) x hoi. ((hieu vien) or (thieu nien)) dai truc van khang di su triet".
• Adding a wildcard symbol may retrieve word variants: su sach ((v nang) OR (vu nang)) x hoi. ((hieu vien) or (thieu nien)) dai truc van khang di su triet*.