Perhaps you should try some spelling variations:
van khanh » van thanh, van hanh, van anh
thien cac » thien cau, thieu cac, trien cac
su triet » su viet, su tien, ve triet
khanh di » khanh bui, khanh duy, thanh doi
truc van » truc va, thuc van, truc ban
hien cac » vien cac, hieu cac, dien cac
vu nang » vuc nang, va nang, vu dang
su sach » so sach, vu sach
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 ((hien cac) OR (thien cac)) truc van khanh 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 ((hien cac) OR (thien cac)) truc van khanh 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 ((hien cac) OR (thien cac)) truc van khanh di su triet".
• Adding a wildcard symbol may retrieve word variants: su sach ((v nang) or (vu nang)) x hoi. hieu ((hien cac) OR (thien cac)) truc van khanh di su triet*.