OKLAHOMA CITY, 2017-Jun-03 — /EPR Retail News/ — Sonic Corp. (NASDAQ:SONC), the nation's largest chain of drive-in restaurants, today (Jun 2, 2017) announced that the company will be presenting at the following investor conferences: On Tuesday, June 13, 2017, the Company will present at the William Blair 37th Annual Growth Stock Conference at the Four Seasons…