This site has been designed to satisfy the basic requirements of accessibility for a high number of users.
Pages don't include frames.
The main links in each page have been associated with keyboard shortcut (or hotkeys). Here following the keys and the links they are referring to.
The use of this keyboard shortcuts is dependent on the Operative System you have installed on your computer: if it is MS Windows the Keyboard Shortcuts must be preceded by the "Alt" key, instead if it is Apple Systems the Keyboard Shortcuts must be preceded by the "Cmd" key.