The IOS Press Open Library® offers authors an Open Access (OA) option. By selecting the OA option, the article will be freely available in perpetuity from the moment it is published, even if its first online appearance is as a pre-press article prior to publication within an issue. In the Open Library® the article processing charges are paid in the form of an Open Access Fee. Authors will receive an Open Access Order Form upon acceptance of their article. Open Access is entirely optional. Also see our website for more information about this option IOS Press Open Library®.