Perhaps you should try some spelling variations:
thanh vai » thanh hai, thanh van, thanh tai
tu sach » thu sach, su sach, te sach
sach tu » sach thu, cach tu, sach ty
cua tre » cuu tre, cua triet, dua tren
duc van » duc va, duc tan, duc manh
duc ban » duc tan, dua ban, duc man
hieu ve » hieu va, hieu van
tu nang » tru nang, tu nong, tu nano
ve cac » va cac, vien cac
nang o » nang co, nang ho, nang ro
cua te » cua tu
o hoc » co hoc, mo hoc, so hoc

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 tu nang o hoc. hieu ve cac ((duc ban) OR (duc van)) thanh vai ((cua tre) or (cua te))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach tu nang o hoc. hieu ve cac ((duc ban) OR (duc van)) thanh vai ((cua tre) OR (cua te)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "tu sach tu nang o hoc. hieu ve cac ((duc ban) OR (duc van)) thanh vai ((cua tre) or (cua te))".
• Adding a wildcard symbol may retrieve word variants: tu sach tu nang o hoc. hieu ve cac ((duc ban) OR (duc van)) thanh vai ((cua tre) or (cua te))*.