The €6.99 paperback was first released in February 2019 but made it top of the Amazon bestseller list in Italy on December 4.
The anti-government rally was joined by League's allies Brothers of Italy and Forza Italia.
Sunday could see fatal cracks appear in Italy’s coalition government. Here’s how.
Members of 5-Star will hold a ballot on the party's internet platform on Tuesday to decide whether the group should join forces with the Democratic Party, its traditional foe.