Perhaps you should try some spelling variations:
cach thuc » anh thuc, cac thu
cac thuc » cac thu, can thuc, cay thuc
hanh tai » thanh tai, hang tai, han tai
sach ly » sach lo, sach ty, sach hay
hang xa » hoang xa, hang va, hang ca
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: co ((sach ly) or (sach y)) hang xa hoi. hieu ve ((cac thuc) OR (cach thuc)) va hanh tai cuc tre~.
• If you are trying to use Boolean operators, they must be ALL CAPS: co ((sach ly) OR (sach y)) hang xa hoi. hieu ve ((cac thuc) OR (cach thuc)) va hanh tai cuc tre.
• The words AND, OR and NOT may confuse the search; try adding quotes: "co ((sach ly) or (sach y)) hang xa hoi. hieu ve ((cac thuc) OR (cach thuc)) va hanh tai cuc tre".
• Adding a wildcard symbol may retrieve word variants: co ((sach ly) or (sach y)) hang xa hoi. hieu ve ((cac thuc) OR (cach thuc)) va hanh tai cuc tre*.