Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
toc sach » hoc sach, doc sach, thuoc sach
hieu van » thien van, lieu va, hieu ve
cua viet » ca viet, hoa viet, cua vat
hieu va » lieu va, hieu qua
van anh » tuan anh, van minh
y nang » ky nang, ly nang, v nang
nang o » nang co, nang ho, nang ro
vi cua » vai cua, di cua
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: toc sach y nang o hoi. ((hieu van) or (hieu va)) cam xuc ((van anh) OR (van thanh)) vi cua viet~.
• If you are trying to use Boolean operators, they must be ALL CAPS: toc sach y nang o hoi. ((hieu van) OR (hieu va)) cam xuc ((van anh) OR (van thanh)) vi cua viet.
• The words AND, OR and NOT may confuse the search; try adding quotes: "toc sach y nang o hoi. ((hieu van) or (hieu va)) cam xuc ((van anh) OR (van thanh)) vi cua viet".
• Adding a wildcard symbol may retrieve word variants: toc sach y nang o hoi. ((hieu van) or (hieu va)) cam xuc ((van anh) OR (van thanh)) vi cua viet*.