@techreport{NBERr1562,
 title = "The Penn World Table (Mark 5):  An Expanded Set of International Comparisons, 1950-1987",
 author = "Robert Summers and Alan Heston",
 institution = "National Bureau of Economic Research",
 type = "Working Paper",
 series = "Reprint Series",
 number = "1562",
 year = "1991",
 month = "May",
 URL = "http://www.nber.org/papers/r1562",
 abstract = {},
}