Modernism - catholicapologetics.info

Modernism (sspx.org)

Pascendi Dominici Gregis – Encyclical of Pope Pius X on the Doctrine of the Modernists

Lamentabili sane - Syllabus condemning the errors of the modernists - Pius X July 3, 1907

Quanta Cura - Encyclical of Pope Pius IX

The Syllabus of errors condemned by by Pius IX

Oath Against Modernism