Perhaps you should try some spelling variations:
cau thuc » cau truc, can thuc, cau phuc
cuu thuc » cuu tac
hanh tai » thanh tai, hang tai, han tai
tu sach » thu sach, su sach, te sach
sach ty » sach y, sach tu, sach thu
xang xa » lang xa, mang xa, ang xa
hieu ve » hieu va, hieu van
va hanh » van hanh, va thanh, va danh
cuc tre » duc tre, cua tre, cuu tre

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 ty xang xa hoi. ((hieu ve) or (hieu qua)) ((cau thuc) or (cuu thuc)) va hanh tai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: tu sach ty xang xa hoi. ((hieu ve) OR (hieu qua)) ((cau thuc) OR (cuu thuc)) va hanh tai cuc tre.
• Adding a wildcard symbol may retrieve word variants: tu sach ty xang xa hoi. ((hieu ve) or (hieu qua)) ((cau thuc) or (cuu thuc)) va hanh tai cuc tre*.