These resources are probably available as well in your larger local public libraries.
Philadelphia Business Journal Book of Business Lists
REF HC108.P5B66 yr.2014 or current year
For full-text and search features for the Philadelphia Business Journal use
Encyclopedia of Associations
This will give you professional associations for all fields, as well as trade shows, and trade publication titles each produces. Start with the Keyword/Name Index volume, then select one, which should put you in the section with similarly useful organizations.