http://www.tandfonline.com/doi/pdf/10.1080/09692290.2016.1268189
https://www.imf.org/~/media/Files/Publications/PP/2019/PPEA2019007.ashx
https://www.imk-boeckler.de/download-proxy-for-faust/download-pdf?url=http%3A%2F%2F217.89.182.78%3A451%2Fabfrage_digi.fau%2Fp_imk_report_159e_2020.pdf%3Fprj%3Dhbs-abfrage%26ab_dm%3D1%26ab_zeig%3D8946%26ab_diginr%3D8482
https://images.transparencycdn.org/images/2022-Report-Up-to-the-task.pdf