Anniversary history

  Title     Date of publication  
DPRI 60 years' history November 1, 2011
DPRI 50 years' history April 1,2001
DPRI 45 years' history November 1,1996
DPRI 40 years' history October 31,1991
DPRI 35 years' history December 6,1986
DPRI 30 years' history October 31,1981
DPRI 25 years' history October 30,1976
DPRI 20 years' history November 24,1971
DPRI 15 years' history October 31,1966
DPRI 10 years' history November 25,1961