according to The Conclave: A Sometimes Secret and Occasionally Bloody History of Papal Elections, by prominent Catholic historian Michael Walsh Michael Walsh (Rowman & Littlefield, 2003).

That ancient and mysterious undertaking known as the "conclave" invariably ... of future papal elections, or conclaves. Under that law, the cardinals were to meet in secret to select the pope's ...

That ancient and mysterious undertaking known as the "conclave ... issued a papal bull known as Ubi periculum setting some rules for the organization of future papal elections, or conclaves. Under ...

That ancient and mysterious undertaking known as the "conclave ... papal elections, including keeping the proceedings secret from the public. Miles Pattenden, an Oxford University history ...