Global Catholic Network
Global Catholic Network:encyclical of Pope Gregory Xvi: Propagation of the Faith
An 1840 letter/Encyclical from the Pope to Catholic leaders encouraging them to continue spreading the Catholic faith despite "them" (revolutionary and liberal hinderances).
Other
Encyclical of Pope Gregory Xvi on Civil Obedience
A letter/Encyclical from Pope Gregory XVI to the Catholic leadership of Poland condemning their revolutionary uprising and asking them to submit to their monarch.