www.lowenstein.com/news-insights/podcasts-listing/what-every-start-up-should-know-about-stock-options#page=1
www.dlapiper.com/en-ma/insights/publications/2023/01/everything-you-need-to-know-about-stock-options
See also:
carpenterwellington.com/post/an-overview-of-preferred-stock-for-startup-lawyers/