the new portion is lines - none of the rest of the class definition needs to change the class definition for article (with line continuations added to fit the code on the pageis class article(object)def __init__(selfauthorlastauthorfirstarticletitlejournaltitlevolumepagesyear)self authorlast authorlast self authorfirst authorfirst self articletitle articletitle self journaltitle journaltitle self volume volume self pages pages self year year def make_authoryear(self)self authoryear self authorlast (self year +') def write_bib_entry(self)return self authorlast 'self authorfirst (self year ')'"self articletitle ',self journaltitle 'self volume 'self pages this code looks nearly the same as that for the book classwith these exceptionssome attributes differ between the two classes (booksfor instancedo not have journal titlesand the method write bib entry is different between the two classes (to accommodate the different formatting between article and book bibliography entriessee bibliog py in course files/code files for the code