The Belgian union catalogue of periodicals

The paper describes the edition, on computer output microfiche, of the supplement to the 1965 Union catalogue of foreign periodicals in Belgian and Luxemburgian libraries and documentation centers. The microfiches contain location information of 28,000 periodicals in 300 libraries and are edited in a rich typography. The paper discusses the coding of the bibliographic fields, the computer processing and formulates some forecasts for the near and further future.