Big Fan

My son, Bradley, is a huge fan of yours and is making his way through all of your books making it his summer challenge to finish them all and is well on his way. Is there a way I could buy a signed copy of one of your books for his birthday coming up May 2nd? He is starting junior high next year and your books are what have transitioned him to chapter books, and he is hoarding them from the school and local library. I know he would love to expand his own collection. Thanks for exciting an avid reader, so much so, he’s getting my husband to read them too!  
Thank you for your time,

Audrey