
https://www.imf.org/en/Publications/fandd/issues/2022/09/Bullet-train-Adrian-Mancini-Griffoli

https://ecipe.org/wp-content/uploads/2024/02/ECI_OccasionalPaper_02-2024_LY02.pdf

https://www.cps.org.uk/files/reports/original/201001000814-CPSUPWARDLYMOBILE2.pdf