Dascher, Paul E.:The Penn Central Revisited: A Predictable Situation.Financial Analysts Journal,1 January 1972, 28. vsk, nro 2, s. 61–64.JSTOR:4470905Artikkelin verkkoversio.
Dascher, Paul E.:The Penn Central Revisited: A Predictable Situation.Financial Analysts Journal,1 January 1972, 28. vsk, nro 2, s. 61–64.JSTOR:4470905Artikkelin verkkoversio.