Perhaps you should try some spelling variations:
su triet » su viet, su tien, ve triet
thuc van » thuc vat, thuc dan, thuc va
truc van » truc va, truc ban, truc dan
hang vi » hang va, hanh vi, hang di
su sach » so sach, vu sach
hieu ve » hieu va, hieu van
va nang » van nang, da nang, cam nang
v nang » vu nang, van nang, voi nang
ve cac » va cac, vien cac
x hoi » xa hoi, o hoi, x ho
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: su sach ((v nang) OR (va nang)) x hoi. hieu ve cac ((truc van) or (thuc van)) hang vi su triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach ((v nang) OR (va nang)) x hoi. hieu ve cac ((truc van) OR (thuc van)) hang vi su triet*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "su sach ((v nang) OR (va nang)) x hoi. hieu ve cac ((truc van) or (thuc van)) hang vi su triet*".