478 A.2d 510 Mary B. Card, Petitioner v. Commonwealth of Pennsylvania, Pennsylvania School Employes’ Retirement Board, Respondent. Commonwealth Court of Pennsylvania.Argued February 1, 1984 July 12, 1984. Public School Employes’ Retirement Board — Purchase of retirement credits — Public School Employes’ Retirement Code of 1959, P.L. 350 — Field, of education — Instruction of subordinates […]