There are 411 fiction titles in the Collection Petit Format imprint from publisher Les Editions Moderne of Montreal. Only two are paperback originals and only one is by a Canadian author. It happens that one book is in both categories - Le mouchoir d'Alencon (The Alencon Handkerchief) by Georges Monarque (1893-1946). Monarque was a lawyer and history buff. As far as I can see this his only novel - published three years after his death. The other PBO is discussed here.