As a member of the School of Translators he helped Alvaro de Oviedo translate the version of Ibn Aben Ragel's
Liber de Judiciis Astrologiae (
Libro conplido en los iudizios de las estrellas), a treatise on judicial astrology that was used by Edigio de Tebladis de Parma and Pietro de Reggio. He also translated the
Lapidario, helped by the Christian Garci Pérez, and the famous
Alfonsine tables, compiled by
Isaac ibn Sid, that provided data for computing the position of the Sun, Moon and planets relative to the fixed stars. Other works attributed to him are the
Tratado de la açafeha into Latin,
Tetrabiblon or Quatriparito (
Ptolemy), 15 treatises on astrology (effects of stars on man and properties of 360 stones with which to ward off negative astral influences), the
IIII libros de las estrellas de la ochaua espera, the
Libro de las cruces and the
Libros del saber de Astronomía. == Mission to Portugal ==