Dear Sir/ Madam, I would like to have a certificate of participation in the DRUID 2023 Lisbon. I would appreciate it if it's possible for me to have a digital copy of the certificate. Here is the detail of my presentation session: Presenter of the paper: 70142, How Friends Become Foes: Complementors and Market Entry in New Technological Generations, 23, 2023-Jun-10, 15:00 - 16:30 Please let me know if any further information is required. Thank you very much in advance. Best regards, Chang Liu [La tua firma pu? scrivere un futuro. Aiuta gli studenti meritevoli a costruire il proprio. Dai il tuo 5x1000 alla Bocconi C.F. 80024610158] <https://giving.unibocconi.it/5x1000> Please note that the above message is addressed only to individuals filing Italian income tax returns. 5x1000 is a percentage of Italian personal income tax that taxpayers can allocate to Universities, scientific research and non profit organizations.