Historically the communication of the results of scientific research in a peer-reviewed journal played as a distinctive seal in the scientific communication. However, such results have also been communicated in many other forms; recently the models for scientific communication have been updated to include the access to online publications, videoconferences, e-mailing discussion lists, news boards, e-mail, and access to electronic documents. With the advent of the first scientific journals by the end of the 18th century it allowed the creation of a flexible channel of publication, with an increasing value until our present days, that made easy, both, the recording of ideas and the exchange of ideas and experiences among scientists. Nowadays the Internet network has stimulated the offer to alter the traditional channels of communication; it came to take care of (release) the anxiety of scientists and other academics to disseminate fastly their knowledge and to learn knowledge from the studies and research of others, likewise it contributes to diminish the problem of the difficulty to locate and access grey literature documents. At the beginning of the 1990s decade, in the pure sciences, remarkedly in physics a new channel has come on board that has been conducive to the dissemination and full access to the research results. They have been named "e-print" servers or archives, and they have been converted into an autonomous circuit of information with its own rules of functioning, cristalizing in a primary source of information and a labour tool of inestimable value.