Format: 

Author, A. A. (Year, Month). Title of paper. Paper presented at the meeting of Organization Name, Location.

Author, A. A. (Year, Month). Title of paper. Paper presented at the meeting of Organization Name, Location. http://dx.doi.org/xxxxx or Retrieved from URL

Examples: 

Oram, D. (2009, May). Considering sustainability through ethical approaches and their practical application. Paper presented at 2009 IEEE International Symposium on Technology and Society (ISTAS), Tempe, AZ. Retrieved from http://dx.doi.org/10.1109/ISTAS.2009.5155906

In-text: (Oram, 2009, p10)

Source:
APA - 7.04, no. 37
APA (ER) - no. 35