This paper presents the results of a first approach to study the science base of recent technological developments. Using the references in U.S. patents given to scientific literature (by patent examiners), we explore the possibility of identifying this science base. These "citation linkages" between science and technology are studied for two datasets: all 1985 U.S. patents (worldwide invented) in the fields of chemical technology and pharmaceuticals; and all Dutch (Netherlands)-invented U.S. patents for all fields of technology, for the period 1982-1985. With this latter dataset, we focus on differences in science-base characteristics between two major technological fields: chemical technology and electrical/electronics technology. After the analysis of some basic characteristics of the cited scientific literature, first approaches to the development of several types of science-base indicators are presented. The problem of calculation of the activity index for small to medium-sized countries is signalled and a remedy is proposed and applied. With help of age distributions of patent references to scientific literature and the number of these references per patent, interesting differences between countries have been found. Comparison of the Netherlands and other countries reveals some first indications of the position of the Netherlands in recent chemical technology. We also investigated the distribution of references to journals for different product groups. References are widely spread among journals. No clear field- or product-specific clusters of journals have been identified, although some journals show "core-like" properties. Furthermore, the distribution of the number of references per patent is found to be highly skewed. We conclude that the analysis of examiner-given references has yielded interesting results, but that the analysis of inventor-given references is a necessary further step in the study of the science base of technological developments.