Wolfgang Glänzel Bart Thijs Koenraad Debackere Citation Classes: A Distribution-based Approach for Evaluative Purposes. 335-360 2019 Springer Handbook of Science and Technology Indicators https://doi.org/10.1007/978-3-030-02511-3_13 books/sp/19/GlanzelMST2019 db/books/collections/GlanzelMST2019.html#GlanzelTD19