Perhaps you should try some spelling variations:
sach tru » sach truc, sach thu, sach tu
tru nang » tra nang, tri nang, truc nano
cham cuu » cap cuu, chat cua
van hanh » van thanh, ban hanh, van anh
so sach » so sanh, bo sach, co sach
hieu ve » hieu va, hieu van
ve cham » va cham, ve chat, vu cham
vai cua » dai cua, hai cua, lai cua
vi cua » di cua
x hoi » xa hoi, o hoi, x ho
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 tru nang ((x hoi) or (o hoc)). hieu ve cham cuu van hanh ((vi cua) or (vai cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: so sach tru nang ((x hoi) OR (o hoc)). hieu ve cham cuu van hanh ((vi cua) OR (vai cua)) triet.
• Adding a wildcard symbol may retrieve word variants: so sach tru nang ((x hoi) or (o hoc)). hieu ve cham cuu van hanh ((vi cua) or (vai cua)) triet*.