339 A.2d 188 Workmen’s Compensation Appeal Board of the Commonwealth of Pennsylvania and Eastern Express, Inc. v. Pearl E. Hoffman, Executrix of the Estate of Marvin E. Hoffman, Appellant. Commonwealth Court of Pennsylvania.Argued May 8, 1975 June 11, 1975. Workmen’s compensation — Petition to terminate agreement — Burden of proof — Cause of disability — […]