Perhaps you should try some spelling variations:
van hanh » van thanh, ban hanh, van anh
so sach » so sanh, bo sach, co sach
sach tu » sach thu, cach tu, sach ty
tu nang » tru nang, tu nong, tu nano
hieu ve » hieu va, hieu van
xuc van » duc van, luc van, vuc van
vai cua » dai cua, hai cua, lai cua
ve cam » ve cham, ve cac, va cam
vi cua » di cua
o hoc » co hoc, mo hoc, so hoc

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

• Performing a fuzzy search may retrieve terms with similar spellings: so sach tu nang ((x ho) or (o hoc)). hieu ve cam xuc van hanh ((vi cua) or (vai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach tu nang ((x ho) OR (o hoc)). hieu ve cam xuc van hanh ((vi cua) OR (vai cua)) triet.
• Adding a wildcard symbol may retrieve word variants: so sach tu nang ((x ho) or (o hoc)). hieu ve cam xuc van hanh ((vi cua) or (vai cua)) triet*.