Este archivo se encuentra en el dominio público en los Estados Unidos porque fue publicado en ese país entre los años 1929 y 1977 (ambos incluidos) sin haber indicado un aviso de derechos de autor. A menos que su autor haya fallecido años antes, se mantiene bajo propiedad intelectual en los países o zonas que no aplican la regla del plazo más corto para las obras estadounidenses, como Canadá (50 años p.m.a.), China continental (50 años, a excepción de Hong Kong o Macao), Alemania (70), Suiza (70), México (100) y otros países con reglas particulares. Vea esta página y este diagrama como referencia e información.
After researching this and some of the other Sound 10 Surveys and promotional photos given to listeners, I found that WCFL and/or the Chicago Federation of Labor did not mark any of this material with any type of copyright mark or other notification.
There are no copyright marks or statements on either side of this survey. What is seen on the other side of it at the lower right is a mark indicating that the material was printed by union printers. (This would be in keeping with a radio station owned and operated by a union.) WCFL AM was sold by the Chicago Federation of Labor in 1978. The call letters disappeared from AM Radio in 1987.
The item can be dated by the information on the other side of the survey at the link above, "Week ending October 6, 1966".
Uploaded a work by WCFL/Chicago Federation of Labor from # [http://www.fabfourfaq.com/pics/big/stagghitline-big.jpg Fab Four FAQ] WCFL Radio/Chicago; [http://www.fabfourfaq.com/pics/big/sound10survey-big.jpg Other side of Sound 10 Survey] # Uploaded to English Wikipedia by {{uv|We hope|w:en:}}: {{original upload date|2010-07-28 20:03}} with UploadWizard