The book Cantos de vida y esperanza by Rubén Darío contains:

    Preface
    I am the one who yesterday said no more
    Optimist's greeting
    To King Óscar
    The three wise men
    Cyrano in Spain
    Salutation to Leonardo
    Pegasus
    To Roosevelt
    Towers of God! Poets!
    Song of hope
    While you have, oh, black hearts
    Helios
    Spes
    Triumphal march

Félix Rubén García Sarmiento, known as Rubén Darío (Metapa, today Ciudad Darío, Matagalpa, January 18, 1867-León, February 6, 1916), was a Nicaraguan poet, journalist and diplomat, the highest representative of literary modernism in the Spanish language . It is, perhaps, the poet who has had greater and more lasting influence on the poetry of the twentieth century in the Hispanic field. He is called prince of the castilian letters.

Note:
The text was extracted from https://es.wikisource.org/wiki/Cantos_de_vida_y_esperanza
under license https://creativecommons.org/licenses/by-sa/3.0/deed.es
In addition, the author is more than 100 years deceased (1916) so it is considered public domain.