Automated Exploratory Clustering. - Georg Stefan Schlake; Max Pernklau; Christian Beecks (IEEE Big Data, 2024)

Towards Ptolemaic metric properties of the z-normalized Euclidean distance for multivariate time series indexing. - Max Pernklau; Christian Beecks (ICDEW, 2024)

Extending K-Means Clustering with Ptolemy's Inequality. - Max Pernklau; Nikita Averitchev; Christian Beecks (BTW, 2025)