These states, defined as eigenvectors of the lowering operator and forming an overcomplete family, were introduced in the early papers of John R. Klauder, e.g.
United States | Republican Party (United States) | Democratic Party (United States) | United States House of Representatives | President of the United States | United States Senate | United States Navy | United States Army | Supreme Court of the United States | United States Air Force | Native Americans in the United States | United States Congress | 66th United States Congress | 74th United States Congress | 18th United States Congress | 73rd United States Congress | 54th United States Congress | 61st United States Congress | United States Marine Corps | United States Department of Defense | 64th United States Congress | 65th United States Congress | 53rd United States Congress | 52nd United States Congress | 55th United States Congress | United States Army Corps of Engineers | 68th United States Congress | United States dollar | Confederate States of America | 56th United States Congress |
This fact is easily verified by using the formula for Bf along with the standard formula for the Husimi function in terms of coherent states.