Perhaps you should try some spelling variations:
day thanh » dao thanh, dat thanh, da thanh
thanh va » thanh van, hanh va, thanh ha
tay lang » tai lang, tay tang, tay quang
cac thuc » cach thuc, cac thu, can thuc
thuc day » thuc dan, thuc vat
bo sach » co sach, hoc sach
ty lang » ty xang, ty hang, tu lang
cua tre » cua te, cuu tre, cua triet
hieu ve » hieu va, hieu van
ve cac » va cac, vien cac
cua tu » cua tuc, cua su, cua cu

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: bo sach ((ty lang) OR (tay lang)) xa hoi. hieu ve cac thuc day thanh va ((cua tre) or (cua tu))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: bo sach ((ty lang) OR (tay lang)) xa hoi. hieu ve cac thuc day thanh va ((cua tre) OR (cua tu))*.
• The words AND, OR and NOT may confuse the search; try adding quotes: "bo sach ((ty lang) OR (tay lang)) xa hoi. hieu ve cac thuc day thanh va ((cua tre) or (cua tu))*".