ISA-SFL War

After Wollheim published details of his lack of payment by Gernsback for the story "The Man from Ariel" in the Terrestrial Fantascience Guild Bulletin, he and several others were expelled from the SFL. Referring to themselves as the XSFL and then as the International Science Association (ISA). Wollheim used this group to attack Gernsback's Wonder Stories as well as Hornig's Fantasy Magazine. Speer credits the ISA with bringing about the sale of Wonder Stories in 1936 to Ned Pines.