The link below is the book used in the class: https://bcs.wiley.com/he-bcs/Books?action=chapter&bcsId=1245&itemId=0471164372&chapterId=1507
Overloading of operators >> https://pt.stackoverflow.com/questions/61034/o-que-%C3%A9-sobrecarga-de-operadores
Composition >> https://pt.stackoverflow.com/questions/25619/composi%C3%A7%C3%A3o-e-agrega%C3%A7%C3%A3o-quais-as-diferen%C3%A7as-e-como-usar
Deitel e Deitel (Portugues) >> c-como-programar-5-ediao-deitel_compress.pdf