It is an anonymous work or pseudonymous work and 50 years have passed since the date of its publication
It is a collective audiovisual or photographic work and 50 years have passed since the date of its publication (or creation, whatever date is the latest)
It is another kind of work, and 50 years have passed since the year of death of the author (or last-surviving author)
Captions
Portrait photograph of Daniel Salamanca, president of Bolivia from 1931 to 1934.
Retrato fotográfico de Daniel Salamanca, presidente de Bolivia entre 1931 y 1934.