In 1917, the year of his graduation, he published his first book of poems, Há uma Gota de Sangue em Cada Poema (There is a drop of blood in each poem), under the pseudonym Mário Sobral.
1917, im Jahr seines Abschlusses am Konservatorium, veröffentlichte er seinen ersten Gedichtband: Há uma Gota de Sangue em Cada Poema ‚In jedem Gedicht gibt es einen Blutstropfen‘, unter dem Pseudonym Mário Sobral.