The annual Value Investor Conference is one of the premier events surrounding Berkshire Hathaway's annual meeting in Omaha. The Motley Fool's Michael Olsen and Rex Moore were in attendance and talked to several value investors. In today's video, Michael chats with Bob Robotti, founder of Robotti & Co., about two Canadian stocks he likes: Calfrac Well Services and Trican Well Service. Robotti says Canada may be the place to look for value in the energy sector.