Warnepieces: Observation balloons in the Great War
Tethered balloon - Wikiwand
The Modelling News: "The flying sausage" or "Pigs do fly!" - Pig Model's Parsival-Sigsfeld German "Drachen" Observation Balloon in 1/144th scale preview...
ALBERT CAQUOT - The New York Times
Balloons and Dirigibles in WWI | National WWI Museum and Memorial
File:ObservationBalloonPozieresJuly1916.jpeg - Wikipedia