A research doujinshi published by Animedia in 1978, primarily focused on Gamba no Bouken. Includes a staff interview (apparently including Osamu Dezaki), as well as an interview with Rihoko Yoshida.
More info: https://k.mandarake.co.jp/auction/item/itemInfoJa.html?index=436217 http://www5d.biglobe.ne.jp/~megasan/gambasite/gambasite2/goods2.htm