«Shades of Line 12: Maya Train timelines not realistic, say private firms». Mexico News Daily. 28 de junio de 2021. Consultado el 10 de diciembre de 2021. «A market survey conducted by Fonatur, PricewaterhouseCoopers and other consultants in 2019 found that a majority of 21 construction companies believed that a period of at least 36 months was needed to build a 250-kilometer section of railroad – provided everything went smoothly. However, "companies with more experience in the construction of railroad tracks favor a period between 36 and 48 months", the survey report said.»
Kitroeff, Natalie; Abi-Habib, Maria; Glanz, James; Lopez, Oscar; Cai, Weiyi; Grothjan, Evan; Peyton, Miles; Cegarra, Alejandro (13 de junio de 2021). «Why the Mexico City Metro Collapsed». The New York Times. Consultado el 10 de diciembre de 2021. «bad welds, critical mistakes that likely caused the crash. That is one of the primary explanations being considered by Mexico City officials, according to several people familiar with the official investigations into the disaster, and it underscores a pattern of political expediency and haphazard work as the metro was being built.»
Equipo de transición de Andrés Manuel López Obrador. «Tren Maya». Archivado desde el original el 29 de noviembre de 2018. Consultado el 29 de noviembre de 2018.
Equipo de transición de Andrés Manuel López Obrador. «Tren Maya». Archivado desde el original el 29 de noviembre de 2018. Consultado el 29 de noviembre de 2018.
