Perhaps you should try some spelling variations:
thu sach » tu sach, thuat sach, thuoc sach
va triet » va thiet, va trien, cua triet
ve triet » va trien, su triet
va chat » van chat, va phat, cao chat
goc va » hoc va, doc va, uoc va
y nang » ky nang, ly nang, v nang
loc va » hoc va, luc va
nang o » nang co, nang ho, nang ro
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: thu sach y nang o hoi. lieu va chat ((goc va) or (loc va)) hanh kem ((va triet) OR (ve triet))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: thu sach y nang o hoi. lieu va chat ((goc va) OR (loc va)) hanh kem ((va triet) OR (ve triet)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "thu sach y nang o hoi. lieu va chat ((goc va) or (loc va)) hanh kem ((va triet) OR (ve triet))".
• Adding a wildcard symbol may retrieve word variants: thu sach y nang o hoi. lieu va chat ((goc va) or (loc va)) hanh kem ((va triet) OR (ve triet))*.