is publish anonymously or under a pseudonym, copyright shall subsist until fifty years from the beginning of the calendar year next following the year in which the work was first published:

        Provided that in the event of the identity of the author becoming known, the duration of copyright shall be calculated in accordance with subsection (1).

         (4)   In this section, a reference to "author" shall, in the case of a work of joint authorship, be construed as a reference to the author who dies last.

18.    Duration of copyright in published editions.

         Copyright in a sound recording shall subsist until fifty years from the beginning of the calendar year next following the year in which the edition was first published.

19.    Duration in copyright in sound recordings.

         Copyright in a sound recording shall subsist until fifty years from the beginning of the calendar year next following the year in which the recording was first published.

20.    Duration of copyright in broadcasts.

         Copyright in a broadcast shall subsist until fifty years from the beginning of the calendar year next following the year in which the broadcast was first made.

21.    Duration of copyright in photographs.

         Copyright in a photograph shall subsist until fifty years from the beginning of the calendar year next following the year in which the photograph was first published.

22.    Duration of copyright in film.

        Copyright in a film shall subsist until fifty years from the beginning of the calendar year next following the year in which the film was first published.

23.    Duration of copyright in works of Government, Government organizations and international bodies.

        Copyright in a works of Government, Government organizations and international bodies shall subsist until fifty years from the beginning of the calendar year next following the year in which the work was first published.