An article-based cross-disciplinary study of reference literature for indicator improvement

In the nineties of the last century, researchers have applied several indicators to study reference literature of scientific articles. Glänzel and Schoepflin (1999) was the first time to capture and understand the subject characteristics in terms of structure and ageing of cited literature in the sciences and social sciences. Following and extending the pioneer study two decades ago, the present study focuses on how to build efficient instruments for the measurement of relevant aspects related to the ‘hardness’ of science. Apart from the observed general shift towards the use of more recent and indexed literature, the need of more than one single indicator is also detected in this study.