The article describes the steps in analysing all citations of patent documents indicated on the first page of German documents published in 1992. The information was downloaded from the German patent database PATDPA and the study reveals the percentage of cited documents in various time ranges.

This article undertakes a quantitative investigation on the patent applications and the resulting patent documents appearing in English, French, German, Japanese and Russian. Utility model applications filed with the German Patent Office and the Japanese Patent Office are included in this study.