Dra. Estela Cifre de Loubriel wrote "La inmigración a Puerto Rico durante el siglo XIX" which was published in the 1960s. It was microfilmed and can be ordered at a LDS FHC. The film number is 924457 Item 1.

The Cifre de Loubriel book about the Canary Island immigrants is a different book. It was published in the 1990s. I don't believe it was microfilmed by the LDS.