1. ABLER , R. F. , 1984 , Data base initiatives in geography and regional science. Memorandum to Roberta Balstad Miller , national Science Foundation (nSF) , Washington , D.C. , U.S.A. , 20 July 1984 .
2. ABLER , R. F. , 1985 b , national Geographical Information Center. Memorandum to Roberta Balstad Miller , nSF , Washington , D.C. , U.S.A. , 10 July 1985 .
3. ABLER , R. F. , 1986 a , A national Geographical Information and Analysis Center. Memorandum to Roberta Balstad Miller , nSF , Washington , D.C. , U.S.A. , 18 January 1986 .
4. ABLER , R. F. , 1986 b, A national Geographical Information and Analysis Center. Memorandum to David Kingsbury via Roberta Balstad Miller , nSF , Washington , D.C. , U.S.A. , 27 February 1986 .