Regarding Pracheta Gupta  

 Well actually there are quite a few book which state the author's DoB. 'AMAAR JA ACHHE', 'JHEELDANGAR KANYA', 'PANCHASHTI GALPO' to nam a few. The publishers are   Ananda Publishers and Dey's Publishing. About the ISBN number I'm not too sure. I'll let you know if possible. Thanks