Over the past six decades
have passed since the time when the first quasars were discovered that the list
of high-galaxies with their fixture - a black hole at the galactic center
filled with more than 100,000 objects.
However, attempts to
produce a thorough census of powerful radiation sources have so far been
restricted to one fundamental problem. The fact that extreme brightness of
quasars, allowing them to see from a great distance, at the same time playing
on them,
