https://www.hesa.ac.uk/data-and-analysis/publications/finances-2015-16/introduction
https://www.boeckler.de/pdf/p_imk_study_55_2017.pdf
https://www.opendemocracy.net/can-europe-make-it/erik-edman/first-rider-of-apocalypse-silent-taxi-driver?utm_source=Daily+Newsletter&utm_campaign=4fc1da7765-DAILY_NEWSLETTER_MAILCHIMP&utm_medium=email&utm_term=0_717bc5d86d-4fc1da7765-407405485
https://cepr.org/system/files/publication-files/190449-geneva_26_the_art_and_science_of_patience_relative_prices_and_inflation.pdf