- https://docs.scala-lang.org/getting-started/index.html
- https://www.manning.com/books/functional-programming-in-scala
- https://docs.scala-lang.org/getting-started/sbt-track/getting-started-with-scala-and-sbt-on-the-command-line.html
- https://www.baeldung.com/scala/option-type
- https://www.tutorialspoint.com/scala/scala_lists.htm
- https://alvinalexander.com/scala/understanding-scala-collections-hierarchy-cookbook/
- https://docs.scala-lang.org/tour/classes.html
- https://www.geeksforgeeks.org/overriding-tostring-method-in-scala/
- https://docs.scala-lang.org/tour/polymorphic-methods.html
- https://docs.scala-lang.org/overviews/core/string-interpolation.html
- https://alvinalexander.com/scala/iterating-scala-lists-foreach-for-comprehension/
- https://docs.scala-lang.org/tour/package-objects.html
- https://anil.cloud/2017/06/14/optional-parameters-in-scala/
- https://www.oreilly.com/library/view/scala-cookbook/9781449340292/ch01s03.html
- http://eed3si9n.com/learning-scalaz/index.html
- sbt/sbt#2521