[Cin] Blue Banana, again

[Andrea paz]

>  I wonder if we should add a reference to the HSL qualifiers chapter as already noted in email and the forum as pointed out by Andrea?

That might be an idea given the quality of the chapter. However, I am
not convinced to put a link to a book publisher's page (currently on
the market). Could there be problems with this? Could it be considered
an advertisement? It would be different if it were a tutorial made
available by the author on his own site.
Unfortunately, I looked for other alternatives, but found only
simplistic and useless tutorial. At that point better our manual.