THE RUBY WAY, Third Edition (2015)
Chapter 2. Working with Strings
Chapter 3. Working with Regular Expressions
Chapter 4. Internationalization in Ruby
Chapter 5. Performing Numerical Calculations
Chapter 7. Working with Times and Dates
Chapter 8. Arrays, Hashes, and Other Enumerables
Chapter 9. More Advanced Data Structures
Chapter 10. I/O and Data Storage
Chapter 11. OOP and Dynamic Features in Ruby
Chapter 12. Graphical Interfaces for Ruby
Chapter 13. Threads and Concurrency
Chapter 14. Scripting and System Administration
Chapter 15. Ruby and Data Formats
Chapter 16. Testing and Debugging
Chapter 17. Packaging and Distributing Code
Chapter 18. Network Programming
Chapter 19. Ruby and Web Applications
Chapter 21. Ruby Development Tools
Chapter 22. The Ruby Community