Cox details the evidence for the doctrine of the Trinity in the Bible looking dozens of different angles.
Is the Pope the Vicar of Christ? No. by David Cox is a tract explaining why the system of apostolic succession of the Popes is unbiblical and heresy. Topics: Doctrine of Apostolic Succession, Peter as the First Pope, The Authority of Tradition and the Father, the Apostolic Teaching, the Office of Apostle.
Spiritual and Catholicism is a single chapter tract on spiritism (the contact with departed dead humans) and the Roman Catholic Church. One of their principle doctrines is the same as Spiritism, that Mary (now passed away) is available for consultation, help, receiving petitions and asking for help, and this is basically necromancy, and carried the death penalty in the OT. This spiritism is unbiblical.