Samuel, S., & Bocutiu, S. (2017). Programming kotlin: Familiarize yourself with all of Kotlin's features with this in-depth guide. Packt Publishing.

Samuel, Stephen, and Stefan Bocutiu. Programming Kotlin: Familiarize Yourself with All of Kotlin's Features with This In-depth Guide. Birmingham, UK: Packt Publishing, 2017.

Samuel, Stephen, and Stefan Bocutiu. Programming Kotlin: Familiarize Yourself with All of Kotlin's Features with This In-depth Guide. Packt Publishing, 2017.