11 any use of a software program not expressly authorized by the author or his licensees or successors in title is unlawful. CHAPTER IV Period of protection Article 52 – Throughout his lifetime an author shall enjoy the exclusive right to exploit his work in any way whatsoever and to make a financial profit from it. On the death of the author, this right shall subsist for the benefit of his successors in title during the current calendar year and the seventy following years. After this period, the moral rights which are unlimited in time may be exercised by a ministerial department responsible for the conservation and promotion of the national heritage. Article 53 – For works of collaboration, the calendar year taken into account shall be that of the death of the last surviving collaborator. Article 54 – For pseudonymous or anonymous works, the duration of the exclusive right shall be seventy years from the first of January of the calendar year following publication and shall be determined by any method of proof provided for in ordinary legislation, in particular copyright registration. Where the author or authors make themselves known, the duration of the exploitation right shall be that relevant to the category of the work in question and the period of legal protection shall start to run under the conditions set out in Article 52. Article 55 – For staggered publications, Article 52 shall apply to each publication and not to the series as a whole. Article 56 – Pour posthumous works, the duration of the exclusive right shall be seventy years from the first of January of the calendar year following the publication of the work. Where a posthumous work is disclosed during the period referred to in Article 52, the right to exploit the work shall belong to the author’s successors in title. Where disclosure is made after the expiry of this period, it shall belong to the owners, by virtue of succession or on other grounds, of the work, who shall publish it or have it published. The posthumous works must be published separately, except where they constitute only a fragment of a work published previously. They may be added to previously published works by the same author only where the author’s successors in title still have the exploitation right in relation to these works. Article 57 – For a software program, the rights provided by this Law shall be extinguished on the expiry of a period of twenty years from the date on which it was designed. Article 58 – During the period referred to in Article 52, a surviving spouse who has not been declared legally divorced shall, whatever the marital property scheme and regardless of any beneficial use he holds under Article 38 of Law No. 67-030 of 18 December 1967 on marital property schemes on the other property in the estate, enjoy the beneficial use of any exploitation right of which the author has not disposed, without prejudice to the right of maintenance of heirs who are minors or who do not have legal capacity in accordance with the conditions and proportions specified by Article 55 of Law No. 68-012 of 4 July 1968 on inheritance, wills and