Correspondence (1988) with Union of International Associations, CIM, CISS, International Association of Universities, International Catholic Centre for UNESCO, CICT, AIAP, ICSU, Standing Committee of NGOs. Report on the 21st NGO conference (13-17 June 1988), on the seminar on relations between UNESCO and NGOs (12-14 April 1988)
Correspondence (1989) with the Standing Committee of NGOs, ICSU, International Association for the Development of International and World Universities, Union of International Associations, AIAP, ICOM, International Fund for Mutual Assistance in Music, CIM, CICT, ITI
Correspondence (1990) with European Centre for Educational Alliances, International Council on Archives, ARSA, International Association of Universities, COEFA, CISS, AIAP, International Peace Research Association, North East NGOs, CIM, ICOM, NGO Standing Committee (meetings and reports on the 22nd NGO Conference, 11-15 June 1990), ICSU, UOIF
Correspondence and annual agreements between ICPHS and UNESCO: amount of subsidies granted to ICPHS and Diogenes, contracts and conditions, financial and moral reports on the use of funds (1985-1991)
Correspondence and annual agreements between ICPHS and UNESCO: amount of subsidies granted to ICPHS and Diogenes, contracts and conditions, financial reports on the use of funds (1950-1985)
Correspondence and working documents of the ICPHS concerning the sexennial reports of the UNESCO Executive Board on NGOs (1964-1969; 1970-1975; 1976-1982; 1983-1988; 1988-1993)
Correspondence of the General Secretariat with the members of the Bureau (1960): Charles E. Odegaard, Ronald Syme, Silvio Zavala, Felice Battaglia, Jules Marouzeau, Hans R. Hahnloser, R.N. Dandekar; general correspondence
Correspondence with the Federation of Documentation (Index bibliographicus) (1955-1956). Correspondence with international bibliographic companies, especially those published under the auspices of ICPHS (1957-1958)