These resources are probably available as well in your larger local public libraries, as well as in the Paul Robeson Library at Rutgers - Camden.
Philadelphia Business Journal Book of Business Lists
REF HC108.P5B66 yr.2014 or current year
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 entry number, which should put you in the section with similarly useful organizations. There should be more recent editions of this in your large (county) public library. Please call the reference desk (856-225-6034) if you need help finding one.