La primera democracia cristiana en España, 1973.

Entre dos siglos, 1996: t.p. (O. Alzaga) p. 631 (Oscar Alzaga)

Curriculum Vitae, Oscar Alzaga, pdf, Oct. 19, 2011 (Óscar Alzaga Villaamil; b. May 29, 1942, Madrid; dr. in law, Univ. Aut. de Madrid; dir., Dpto. de Derecho Político, UNED; lists works) http://www.uned.es/dpto-derecho-politico/CV%20Oscar%20Alzaga%202011.pdf

Wikipedia.es, Nov. 28, 2011 (Óscar Alzaga Villaamil; b. Madrid, 29 May 1942; jurist, politician, educator)

Del consenso al conflicto permanente, 2011: title page (Óscar Alzaga) flap (catedrático de derecho constitucional y académico de la Real Academia de Ciencias Morales y Política)

Discursos parlamentarios, 2019: p. 16 (heavily involved in development and implementation of the 1977 Spanish Constitución until 1987, when he left politics to dedicate his time to the university and practice of law)