void Author::showInfo(){
    cout<<"     Author "<<surname<<", live in "<<country;
    if(getCount(books) == 0){
        cout<<", and until not has books.."<<endl;
        return;
    }
    if(getCount(books) == 1)
        cout<<", and has a book: "<<endl;
    else{
        cout<<", and has books: "<<endl;
    }
    showAll(books);
}