I believe the page "https://www.euclideanspace.com/physics/dynamics/energy/rigidbody/index.htm" has an error in one of the equations. The first equation in case 3 is the equation for Tgx. The second term on the right hand side of the equation is written as "Ixy(ay - wx wy)". I believe the wy should be wz, giving "Ixy(ay - wx wz)", which makes the equation "Tgx = Ixx ax - Ixy(ay - wx wz) - Ixz(az + wx wy) - (Iyy - Izz)wy wz - Iyz(wy wy - wz wz)".
Thanks very much for this.
Sorry it has taken me so long to reply, something seems to have gone wrong with the forwarding so I have only just seen it. Also I have a few technical problems with my computer at the moment.
I will correct the page as soon as I can.