To the person who replied: Thank you.
I finally found my way into your reference.
However, the resistance split phase motor does not seem to explain the
motor I have.
In the book there is no external inductor.
The two shown are stator windings, if the same symbolism is followed as
for the other motors.
So, my questions remains: what is the external inductor for?
Was there such a thing as an inductor start motor?