Us Magazine With Jabba the Hutt Cover (August 1, 1983)
This August 1, 1983 issue of Us Magazine has Jabba the Hutt on the cover, and a decent article inside about creating many of the aliens used in Return of the Jedi. It has quotes from Phil Tippett, Joe Johnston and others. I have created a PDF file that just includes the Jabba article, so click the magazine above to view it.
One sentence I found interesting was this: “Sound designer Ben Burtt did the vocalizing [for Jabba].” IMDB and many other sites list Larry Ward (apparently a linguist from Berkeley) as the voice as the voice of Jabba. But I have also heard more than one person claim that it was in fact Burtt who did it. Burtt would have been in charge of processing the voice to make it sound so booming and alien, so perhaps this is what is confusing people, but I would like to find something from Burtt directly that explains exactly what went on.