What is the standard APA style for a handout given by a speaker at a conference?
If you have gone to a conference and picked up a handout (or obtained a copy) of a paper or poster presentation and would like to use information from that handout, in section 4.16 (p. 260) the APA Publication Manual does describe how to reference this type of source. They refer to it as an “unpublished paper or presentation.” The format is the same for posters and papers. Just make sure that you indicate whether your source is a poster or a paper.