42 BOOK THREE COPYRIGHT AND RELATED RIGHTS Article 138 For the purposes of this Law, the following terms shall have the meaning given below: (1) Work: Any created literary, artistic or scientific product, whatever its type, mode of expression, significance or purpose of its creation. (2) Creation: The creative nature that confers originality on the work. (3) Author: The person who creates the work. Is considered author of the work the person whose name is indicated on, or attributed to, the published work as being its author, unless proven otherwise. The author may publish his work anonymously or under a pseudonym, provided that the identity of the author can be established without any doubt. In case of doubt, the publisher or producer of the work, whether a natural person or legal entity, shall be the representative of the author in the exercise of his rights until the identity of the latter is disclosed. (4) Collective work: A work made by a group of authors under the instruction of a natural person who, or a legal entity which, undertakes to publish the work under his or its name and direction, provided that the contributions of the participants in such work are integrated in the general objective set by that person or legal entity, in such a manner that it is impossible to distinguish the individual contribution of each. (5) Work of joint authorship: A work which is not considered as a collective work, in the making of which more than one person participated, whether or not it is possible to distinguish the individual contribution of each in the work. (6) Derivative work: A work which is derived from an existing one, such as translations, musical re-arrangements, compilations of works, including readable databases, from the computer or otherwise, and collections of expressions of folklore, which by reason of the arrangement and selection of their contents, are considered as created works. (7) National folklore: Any expression which consists of distinctive elements reflecting the traditional popular heritage, which originated or developed in Egypt, including in particular: (a) Oral expressions such as folk tales, poetry and charades, and other folklore; (b) Musical expressions such as popular songs accompanied by music; (c) Motion expressions, such as popular dances, plays, artistic forms and rituals; (d) Tangible expressions such as: