Using a very nice decription from user @David:  

Neutral and earth are connected together, but in main cabinet side. The Neutral an Earth may be splitted from PEN just once. Then you got three wires, you need to change the entire installation.
In case the PEN wire braaks, there is still dangerous, therefore an earthing rod is needed. In the depiction is named additional source electrode. For further more safety a GFCI can be installed at point where the circuit is splitted with dots in depiction.
What you may not do, is the link you added. You may not connect neutral to earth in the connecting plug of appliance. Also the used terminology is incorrect:

I can NOT use neutral wire as a ground.

Rather, the neutral is splitted from earth (therofore you already have the earth) and not viceversa.

Using a very nice description linked in a comment from user @David: 

(Image source: The IEE, Wiring Matters magazine, issue 16, Autumn 2005)

Neutral and earth are connected together, but in main cabinet side. The Neutral and Earth may be split from PEN just once. Then you have got three wires, so you need to change the entire installation.

In case the PEN wire breaks, there is still danger, therefore an earthing rod is needed. In the image, an "Additional Source Electrode" is shown. For further safety, a GFCI can be installed at the point where the circuit is split with dots in the image.

What you may not do, is the link you added. You may not connect neutral to earth in the connecting plug of an appliance. Also the used terminology is incorrect:

I can NOT use neutral wire as a ground.

Rather, the neutral is split from earth (therefore you already have the earth) and not vice-versa.