Impossible to Search from website

[Carlos Lopez Gonzalez <carloslopezgonzalez yahoo es>]

Every time I try to use the Search resource form the stable documentation:

http://developer.gnome.org/gtkmm-tutorial/stable/

I get this:

We're sorry...

... but your computer or network may be sending automated queries. To protect our users, we can't process your request right now.

See Google Help for more information.

Any way to fix it?
Thanks
Carlos