References
- https://sites.google.com/site/dataclusteringalgorithms/quality-threshold-clustering-algorithm-1
- https://www.coursera.org/learn/parprog1/programming/akLxD/k-means
- US, UK & German city data derived from http://people.sc.fsu.edu/~jburkardt/datasets/cities/cities.html
- US voting data sourced from https://forge.scilab.org/index.php/p/rdataset/source/tree/main/csv/cluster/votes.repub.csv