Isidore de Lara: Biographical sketch with links to related material, partial list of operas, and details of his affair with Princess Alice of Monaco from Wikipedia.
Isidore de Lara: Listing at The Lied and Art Song Texts Page with linked to selected vocal texts.
Lara, Isidore de: Biography showing studies, major genres, private patronage, and promotion of new music from the Grove Concise Dictionary of Music entry at WQXR radio.
Lara, Isidore de: Listing at JewishEncyclopedia.com from the Jewish Yearbook of 1901 notes some of the works he'd composed by that time.