Immutable
Версия 3.1 от Alexandr Fokin на 2022/01/09 21:58
All About C# Immutable Classes. (Про иммутабельность в целом, а не про коллекции)
https://www.c-sharpcorner.com/article/all-about-c-sharp-immutable-classes2/
Functional C#: Immutability
https://habr.com/ru/post/266873/
Difference between ImmutableArray<T> and ImmutableList<T>
https://stackoverflow.com/questions/22349861/difference-between-immutablearrayt-and-immutablelistt