Perhaps you should try some spelling variations:
cau thuc » cau truc, cuu thuc, can thuc
vat hanh » vat thanh, van hanh, va hanh
tu sach » thu sach, su sach, tu cach
te sach » toc sach
hieu ve » hieu va, hieu van
cua tre » cua te, cua triet, dua tren
cuu tre » cau tren, cau treo
ve cau » ke cau, va cau, ve cac
x hoi » xa hoi, o hoi, x ho

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) or (te sach)) ky nang x hoi. hieu ve cau thuc vat hanh vi ((cua tre) OR (cuu tre))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: ((tu sach) OR (te sach)) ky nang x hoi. hieu ve cau thuc vat hanh vi ((cua tre) OR (cuu tre)).
• The words AND, OR and NOT may confuse the search; try adding quotes: "((tu sach) or (te sach)) ky nang x hoi. hieu ve cau thuc vat hanh vi ((cua tre) OR (cuu tre))".
• Adding a wildcard symbol may retrieve word variants: ((tu sach) or (te sach)) ky nang x hoi. hieu ve cau thuc vat hanh vi ((cua tre) OR (cuu tre))*.