Vollbehr Collection of Incunabula: Hearing Before the Committee on the Library, House of Representatives, Seventy-first Congress, Second Session, on H.R. 6147, a Bill Authorizing the Secretary of the Treasury to Pay to the Joint Committee on the Library the Sum of $1,500,00 for the Purchase of the Collection of Three Thousand Incunabula to be Deposited in the Library of Congress and Known as the Herbert Putnam Collection of Incunabula. March 10, 1930