Johnston's bibliography is the best place to go to get information on William Burroughs's interaction with Auerhahn Press. The second volume of Burroughs's letters has just come out and it includes a handful of correspondence between Burroughs and Haselwood.
The relationship of the two men deteriorated when Haselwood balked at publishing The Exterminator II. One dose of the cut ups was enough for Haselwood. The cut ups were tough medicine. At one point Burroughs wrote five increasingly irate letters to Haselwood to get information on future publication and royalities. Here is the fifth letter which was mentioned but not included in Johnston. It is a rare instance of a pissed off Burroughs.
Feb 24, 1961
9 Rue Git Le Coeur
Paris 6, France
Dear Dave Haselwood:
You seem to be running a mighty loose ship. This is the fifth letter I have sent you to inquire about a manuscript sent six months ago. Now I hear through J. Montgomery that you do not intend to publish Exterminator II. I consider your behavior discourteous. sloppy business practice, dishonest, and down right stupid. Is that clear enough or shall I make it even clearer? Will you please return my manuscript right now like today.
Haselwood responded to this letter and sent Burroughs a royalty check. The beast was calmed to a certain extent, even admiting to Haselwood "[j]ust as well I think the other material was not published in that form."