Wikipedia cites extensions by other authors to the canonical "Three laws" as follows
There are two Fourth Laws written by authors other than Asimov. The 1974 Lyuben Dilov novel Icarus's Way (a.k.a. The Trip of Icarus) introduced a Fourth Law of robotics:
A robot must establish its identity as a robot in all cases.
Dilov gives reasons for the fourth safeguard in this way: "The last Law has put an end to the expensive aberrations of designers to give psychorobots as humanlike a form as possible. And to the resulting misunderstandings..."
For the 1986 tribute anthology Foundation's Friends Harry Harrison wrote a story entitled, "The Fourth Law of Robotics". This Fourth Law states:
A robot must reproduce. As long as such reproduction does not interfere with the First or Second or Third Law.
In the book a robot rights activist, in an attempt to liberate robots, builds several equipped with this Fourth Law. The robots accomplish the task laid out in this version of the Fourth Law by building new robots who view their creator robots as parental figures.
A fifth law was introduced by Nikola Kesarovski in his short story "The Fifth Law of Robotics". This fifth law says:
A robot must know it is a robot.
My interest is primarily focused on the first of the 4th laws (4a if you prefer) and the 5th law.
Was Asimov made aware of these extensions during his lifetime and is there any documented evidence to support any opinion he had on them?