Perhaps you should try some spelling variations:
van thanh » ban thanh, van tuan
van hanh » ban hanh, van anh, van ban
sach ty » sach y, sach thu, xach tay
sach tu » sach thu, cach tu, sach uu
cua tre » cua te, cuu tre, cua triet
nang o » nang co, nang ho, nang ro
va cam » va cham, va cac, va cao
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: te ((sach ty) or (sach tu)) nang o hoi. lieu va cam xuc ((van hanh) OR (van thanh)) vi cua tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: te ((sach ty) OR (sach tu)) nang o hoi. lieu va cam xuc ((van hanh) OR (van thanh)) vi cua tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "te ((sach ty) or (sach tu)) nang o hoi. lieu va cam xuc ((van hanh) OR (van thanh)) vi cua tre".
• Adding a wildcard symbol may retrieve word variants: te ((sach ty) or (sach tu)) nang o hoi. lieu va cam xuc ((van hanh) OR (van thanh)) vi cua tre*.