Estimations
Why are estimations hard.
https://www.quora.com/Why-are-software-development-task-estimations-regularly-off-by-a-factor-of-2-3
https://medium.com/@Soyale/non-developers-this-is-why-software-estimation-is-hard-a47cca9c2511
https://medium.com/ampersand-lab/why-is-software-effort-estimation-so-difficult-70a6948d58d7
https://techbeacon.com/estimates-are-hard-so-dont-do-them
https://www.ben-morris.com/estimation-pitfalls-why-software-development-estimates-are-so-difficult/
https://www.linkedin.com/pulse/why-estimating-software-development-hard-what-clients-olberding/
https://www.sitepoint.com/10-reasons-why-software-project-estimates-fail/
https://www.sitepoint.com/larger-teams-do-not-develop-faster/
https://news.ycombinator.com/item?id=12149515
https://medium.com/@Soyale/non-developers-this-is-why-software-estimation-is-hard-a47cca9c2511
https://www.gun.io/blog/why-are-we-still-so-bad-at-software-estimates
https://www.linkedin.com/pulse/why-estimating-software-development-hard-what-clients-olberding/