Where a work does not carry the name of an author or carries an unknown pseudonym or is published anonymously, the publisher shall be deemed the owner of economic rights of the author for the purposes of exercising these rights until the author reveals his identity.

Where several persons participate in the creation of a work and it is impossible to distinguish the contribution of anyone of them, all such persons shall be considered equally joint owners of such work and no one of such persons shall exercise copyright unless there is a written agreement to the contrary.