Catalog problem - Java

public class catalogoLibros {
    public Libro libros[] = new Libro[20];

    public catalogoLibros(){
        libros[0] = new Libro(false, 1, "JavaScript & jQuery: Interactive Front-End Web Development", "Jon Duckett", null);
        libros[1] = new Libro(false, 2, "Agile Web Development with Rails 4", "Dave Thomas", null);
        libros[2] = new Libro(false, 3, "The Definitive Guide to Django", "Adrian Holovaty", null);
        libros[3] = new Libro(false, 4, "Practical Node.js", "Azat Mardan", null);
        libros[4] = new Libro(false, 5, "MongoDB: The Definitive Guide", "Kristina Chodorow", null);
        libros[5] = new Libro(false, 6, "Pro AngularJS", "Adam Freeman", null);
        libros[6] = new Libro(false, 7, "AngularJS", "Brad Green", null);
        libros[7] = new Libro(false, 8, "Developing Backbone.js Applications", "Addy Osmani", null);
    }
}