Freezolite: the magic gem for keeping Ruby literals safely frozen—Martian Chronicles, Evil Martians' team blog
How to specify `frozen_string_literal: true` - Kazuhiro NISHIYAMA - Rabbit Slide Show
How to specify `frozen_string_literal: true` | PPT
frozen string literalへのデバッグオプション - koicの日記
Using frozen_string_literal and unfreezing a string argument results in Ambiguous positive number operator warning · Issue #4630 · rubocop/rubocop · GitHub
What are Ruby “Frozen String Literals”? | by Sean Robenalt | Medium