Abstract Classes Courses
Devoxx via YouTube Java and Object Oriented programming Essential Training
Udemy Java Tutorial - Abstract Classes and Methods
CodeWithHarry via YouTube Having Fun with Generics and Abstract Classes in C#
NDC Conferences via YouTube Abstract Class and Abstract Methods - Python Programming
Sundeep Saradhi Kanthety via YouTube Abstract Methods and Abstract Class - Java Programming
Sundeep Saradhi Kanthety via YouTube Game Programming - Creating Mobs and NPCs - Episode 90
The Cherno via YouTube Virtual Functions, Pure Virtual Functions, and Abstract Classes in Object-Oriented Programming
CodeBeauty via YouTube Object-Oriented Programming in Kotlin
Pluralsight OOP (course 3): Inheritance, Abstract Classes, Interfaces and other amazing things
SymfonyCasts