2018
https://towardsdatascience.com/dimensionality-reduction-for-dummies-part-2-3b1e3490bdc9
https://towardsdatascience.com/https-medium-com-abdullatif-h-dimensionality-reduction-for-dummies-part-1-a8c9ec7b7e79
2015
https://www.analyticsvidhya.com/blog/2015/07/dimension-reduction-methods/