Hans,

The file samples.tex requests updated bibliography data for some of the samples. Since the file is a few years old, it is not clear if this information has already been provided.

If it is still needed, here are entries for three of the sources and a note on the source of another, along with corrections for a few typos.

The first bibtex entry was lifted from Google Boooks, the other two from the ACM Digital Library.

    @book{dawkins2000unweaving,
      title={Unweaving the Rainbow: Science, Delusion and the Appetite for Wonder},
      author={Dawkins, R.},
      isbn={9780547347356},
      url={http://books.google.com/books?id=ZudTchiioUoC},
      year={2000},
      publisher={Houghton Mifflin Harcourt}
    }
     @book{Hofstadter:1985:MTQ:537101,
      author = {Hofstadter, Douglas R.},
      title = {Metamagical Themas: Questing for the Essence of Mind and Pattern},
      year = {1985},
      isbn = {0465045405},
      publisher = {Basic Books, Inc.},
      address = {New York, NY, USA},
     }
    @book{Tufte:1990:EI:78223,
     author = {Tufte, Edward},
     title = {Envisioning Information},
     year = {1990},
     isbn = {0-9613921-1-8},
     publisher = {Graphics Press},
     address = {Cheshire, CT, USA},
    }

reich.tex is a list of the voice samples from Steve Reich's 1995 composition City Life.

Corrections for dawkins.tex, douglas.tex, and knuth.tex:

In each set, the first line is taken from the current sample file and the second is a correction. The dawkins.tex and douglas.tex corrections are based on scanned images on Google Books, the knuth.tex correction is based on my personal copy of the book (first edition second printing).

dawkins.tex is from pages 145 and 146 of the book
come down head. Everybody on the right had to will it to be
come down heads. Everybody on the right had to will it to be

to sit down. Then those who remained were divided into two,
to sit down. Then those that remained were divided into two,
I also note that all of the quotes in the Dawkins source are single-quotes, not double-quotes as in dawkins.tex, \quote{}, not \quotation{}. This is unusual for a book printed in the USA by an American publisher, so perhaps Dawkins wanted it that way.

douglas.tex is from page 260 of the book
of his forthcoming books, from the typesetting and layout
of his forthcoming books|=|from the typesetting and layout

not become as well known or available.
not become as well known or as available.

Not only is the concept exiting and clearly well executed,
Not only is the concept exciting and clearly well executed,
There are a few other differences, but these are most likely due to publisher's style sheet and the lack of availability of logotypes for TeX and Metafont.

knuth.tex is from page 50 of the book
from the chaff and separate the sheep from the goats.
from the chaff, and separate the sheep from the goats.

--
Rik Kabel