Subsequent to my question about the mis-named book above, I have had an opportunity to
confirm that it is in fact: Magyar Zsido Csaladok Genealogiaja.
Erno Munkacsi was the son of Bernat Munkacsi and they both authored
Magyar Zsido Csaladok Genealogiaja, OR Genealogy of Hungarian Jewish Families,
which is the true name of the book in question:
Genealogical Revelations of Hungarian Jewish Families - First Volume Editor - Munkatchi
It's TRUE name is:
Magyar Zsido Csaladok Genealogiaja, or Genealogy of Magyar Jewish Families written by Munkacsi, Bernat and his son, Munkacsi, Erno.
It details specifically the MUNK and FELSENBURG Hungarian families.
My father is a distant relative of these families.
Erno is the author of "How it Happened....." In my father's genealogy of the Sonnenschein's, he writes:
“Erno was attorney of the Jewish Congregation in Budapest. During the critical year of 1944 he was one of those
Jewish leaders whose political acumen saved the lives of a good part of the Budapest Jewish community.”
There is criticism of Erno (e.g. in Wiki https://en.wikipedia.org/wiki/Erno_Munkacsi) but I believe my father.
Erno and the other leaders of the Budapest Judenrat did what they humanly could to save as many lives as possible.
My father's maternal family, Sonnenschein, are descendants of Chaile Felsenburg, Bernat's grandmother, and my father's great great grand aunt. Chaile (1805 - 1851) married Bernat Munk. Munk was Magyar-ized to Munkacsi; many Jewish families Magyar-ized their names.
I have the full PDF of Magyar Zsido Csaladok Genealogiaja.
I sent the original copy in my possession to the USHMM in 2017.
They have not included it in my father's archive, but his update is there:
Los Angeles, CA