Perhaps you should try some spelling variations:
sach tu » sach thu, cach tu, sach ty
tu nano » truc nano
hieu ve » hieu va, hieu van
cac duc » cac du, cao duc, cac dac
va hanh » van hanh, va thanh, va danh
su sach » so sach, vu sach
ve cac » va cac, vien cac
vi cua » vai cua
di cua » dai cua, doi cua, de cua
x hoi » xa hoi, x ho, 5 hoi
o hoi » co hoi, o hoc, o hai

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 tu nano ((x hoi) or (o hoi)). hieu ve cac duc va hanh ((vi cua) or (di cua)) triet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: su sach tu nano ((x hoi) OR (o hoi)). hieu ve cac duc va hanh ((vi cua) OR (di cua)) triet.
• Adding a wildcard symbol may retrieve word variants: su sach tu nano ((x hoi) or (o hoi)). hieu ve cac duc va hanh ((vi cua) or (di cua)) triet*.