Postage stamps and postal history of Puerto Rico - Wikipedia
1971 8c San Juan for sale at Mystic Stamp Company
5 Tropical Island Forever Stamps For Mailing Florida Caribbean Island – Edelweiss Post
1937 3c Puerto Rico for sale at Mystic Stamp Company
Postage stamp with the image of Puerto Rico flag. Puerto Rico Flag Postage on white background with shadow. Vector Illustration Stock Vector Image & Art - Alamy