When using an href tag and an “&” is present, an error will occur in the HTML stating that it is an “unknown entity section”.
This can be easily solved by replacing the “&” with an “&” everywhere we have it in the URL.
To verify that your HTML is correct, you can verify it using http://validator.w3.org/
P.S Errors in HTML hard your Search Engine Ranking (Your Google Position). Always check your HTML for errors.