For a collaborative work, it is known as a joint work and is created when two or more people contribute copyrightable authorship to a project. All the people who create a joint work own copyright of the work together. The term of protection of copyright for collaborative work is the life of the last author plus 50 years after his or her death. For the copyright to an entrusted work, it is in accordance with the form of contract; or it will under the copyright law to enforce if there is no contract obtained.