Perhaps you should try some spelling variations:
thanh lam » thanh lap, hanh lam, thanh nam
ve triet » va trien, su triet
hieu van » hieu va, thien van, lieu va
va triet » va thiet, va trien, cua triet
va thanh » gia thanh, ban thanh, va tinh
cau duc » cao duc, cau luc, chu duc
tu sach » thu sach, su sach, te sach
van cau » van dau, van hau, van chat
sach ty » sach y, sach tu, sach thu
o lai » o lao
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: tu sach ty xang ((o hoi) or (o lai)). hieu van cau duc va thanh lam ((va triet) OR (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty xang ((o hoi) OR (o lai)). hieu van cau duc va thanh lam ((va triet) OR (ve triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach ty xang ((o hoi) or (o lai)). hieu van cau duc va thanh lam ((va triet) OR (ve triet))".
• Adding a wildcard symbol may retrieve word variants: tu sach ty xang ((o hoi) or (o lai)). hieu van cau duc va thanh lam ((va triet) OR (ve triet))*.