Well, there was a later book that is described as a 'spin-off': https://en.wikipedia.org/wiki/List_of_Who_Fra...abbit_media#Who_P-P-P-Plugged_Roger_Rabbit.3F
Well, there was a later book that is described as a 'spin-off': https://en.wikipedia.org/wiki/List_of_Who_Fra...abbit_media#Who_P-P-P-Plugged_Roger_Rabbit.3F