https://www.investopedia.com/articles/financial-theory/11/valuing-startup-ventures.asp
https://medium.com/datadriveninvestor/understanding-startup-valuation-a393f6fadc6f
https://www.thinklions.com/blog/startup-valuation/
https://medium.com/parisoma-blog/valuation-for-startups-9-methods-explained-53771c86590e
https://www.investopedia.com/ask/answers/difference-between-premoney-and-postmoney/
https://www.entrepreneur.com/article/334805
https://qz.com/work/1349238/the-lean-startup-is-an-unproductive-legend/