Perhaps you should try some spelling variations:
cua triet » cua viet, su triet, va triet
dung tren » dung trong, dung trung
hoc sach » hoc sinh, hoc cac, hoc anh
hieu van » hieu va, thien van, lieu va
van lam » van nam
lam duc » lam duoc, pham duc, nam duoc
va hanh » van hanh, va thanh, va danh
hanh va » hang va, hanh vi
y lang » o lang, tay lang, yen lang
_ lang » o lang, _ land

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

• If you are trying to use Boolean operators, they must be ALL CAPS: hoc sach ((y lang) OR (_ lang)) xa hoi. hieu van lam duc va hanh va ((dung tren) OR (cua triet))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "hoc sach ((y lang) OR (_ lang)) xa hoi. hieu van lam duc va hanh va ((dung tren) or (cua triet))~".
• Adding a wildcard symbol may retrieve word variants: hoc sach ((y lang) OR (_ lang)) xa hoi. hieu van lam duc va hanh va ((dung tren) or (cua triet))*.