314 A.2d 563 Lillian E. Nichols, Appellant, v. Wright’s Truck Stop, Erie Insurance Company, Insurance Carrier, and Workmen’s Compensation Appeal Board, Appellees. Commonwealth Court of Pennsylvania.Argued January 10, 1974 January 29, 1974. Workmen’s compensation — Accident — Sufficient evidence — Burden of proof — Causation — Scope of appellate review — Substantial evidence — Credibility. […]