Donald Knuth citations

Science is what we understand well enough to explain to a computer. Art is everything else we do.
en

A mathematical formula should never be "owned" by anybody! Mathematics belong to God.
en
Digital Typography (1999)

Beware of bugs in the above code; I have only proved it correct, not tried it.
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I define UNIX as 30 definitions of regular expressions living under one roof.
en
Digital Typography (1999)

Programmers waste enormous amounts of time thinking about, or worrying about, the speed of noncritical parts of their programs, and these attempts at efficiency actually have a strong negative impact when debugging and maintenance are considered. We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. Yet we should not pass up our opportunities in that critical 3%.
Variant in Knuth, "Structured Programming with Goto Statements" http://pplab.snu.ac.kr/courses/adv_pl05/papers/p261-knuth.pdf. Computing Surveys 6:4 (December 1974), pp. 261–301, §1.
Knuth refers to this as "Hoare's Dictum" 15 years later in "The Errors of Tex", Software—Practice & Experience 19:7 (July 1989), pp. 607–685. However, the attribution to C. A. R. Hoare is doubtful. http://shreevatsa.wordpress.com/2008/05/16/premature-optimization-is-the-root-of-all-evil/
All three of these papers are reprinted in Knuth, Literate Programming, 1992, Center for the Study of Language and Information ISBN 0937073806
Source: Computer Programming as an Art (1974), p. 671

Vol. II, Seminumerical Algorithms
The Art of Computer Programming (1968–2011)

… If I had a way to rate happiness, I think it's a good design to have an organism that's happy about 80% of the time. If it was 100% of the time, it would be like everybody's on drugs and everything collapses and nothing works because everybody is just too happy. … There are times when I am down and I know that I've actually been programmed to be depressed a certain amount of time.
AI Podcast, December 30, 2019, Algorithms, Complexity, Life, and The Art of Computer Programming https://www.youtube.com/watch?v=2BdBfsXbST8,

Vol. I, Fundamental Algorithms, Section 1.1 (1968)
The Art of Computer Programming (1968–2011)
Source: Leaders in Computing: Changing the digital world

In his video account on the creation of TeX http://www.webofstories.com/people/donald.knuth/52?o=SH, he comments that Xerox offered to allow him to use their equipment, but that the fonts he created would belong to them.

Vol. IV - A, Combinatorial Algorithms, Section 4.2.1.6 (2011)
The Art of Computer Programming (1968–2011)

Donald Knuth, quoted in: Arturo Gonzalez-Gutierrez (2007) Minimum-length Corridors: Complexity and Approximations. p. 99

Jack Woehr. An interview with Donald Knuth http://www.drdobbs.com/an-interview-with-donald-knuth/184409858. Dr. Dobb's Journal, pages 16-22 (April 1996)

Source: Computer Programming as an Art (1974), p. 668

Vol. II, Seminumerical Algorithms, Section 3.3.2 part B, first paragraph (1969)
The Art of Computer Programming (1968–2011)

Digital Typography, ch. 1, p. 8 (1999)

Jack Woehr. An interview with Donald Knuth http://www.drdobbs.com/an-interview-with-donald-knuth/184409858. Dr. Dobb's Journal, pages 16-22 (April 1996)

Knuth versus Email http://www-cs-faculty.stanford.edu/~knuth/email.html

Vol. II, Seminumerical Algorithms, Section 4.2.2 part A, final paragraph [Italics in source]
The Art of Computer Programming (1968–2011)

"Literate Programming", The Computer Journal 27 (1984), p. 97. (Reprinted in Literate Programming, 1992, p. 99.)
Literate Programming (1984)

Vol. I Fasc. 1, "MMIX, a RISC computer for the new millennium"
The Art of Computer Programming (1968–2011)

Donald Knuth's webpage http://www-cs-faculty.stanford.edu/~knuth/faq.html states the line was used to end a memo entitled Notes on the van Emde Boas construction of priority deques: An instructive use of recursion (1977)

[Knuth, Donald, 2002, All Questions Answered, Notices of the AMS, 49, 3, 320, http://www.ams.org/notices/200203/fea-knuth.pdf, PDF]

[Knuth, Donald, 2002, All Questions Answered, Notices of the AMS, 49, 3, 321, http://www.ams.org/notices/200203/fea-knuth.pdf, PDF]

Vol. I, preface (October 1967) to the first edition. (p. x 1973, p. ix 1997)
The Art of Computer Programming (1968–2011)

Digital Typography, ch. 33, p. 649 (1999)

Source: Computer Programming as an Art (1974), p. 673 [italics in source]

Computer Literacy Bookshops Interview http://karthikr.wordpress.com/2006/04/06/donald-knuth-%e2%80%94-computer-literacy-bookshops-interview-1993/ Computer Literacy Bookshops Interview (1993)
On why bioinformatics is very exciting

Source: Computer Programming as an Art (1974), p. 669 [italics in source]

Vol. III, Sorting and Searching, End of index (1973)
The Art of Computer Programming (1968–2011)

Jack Woehr. An interview with Donald Knuth http://www.drdobbs.com/an-interview-with-donald-knuth/184409858. Dr. Dobb's Journal, pages 16-22 (April 1996)

AI Podcast, December 30, 2019, Algorithms, Complexity, Life, and The Art of Computer Programming https://www.youtube.com/watch?v=2BdBfsXbST8,

[...] Without any underlying symmetry properties, the job of proving interesting results becomes extremely unpleasant. The enjoyment of one's tools is an essential ingredient of successful work.
Vol. II, Seminumerical Algorithms, Section 4.2.2 part A, final paragraph [Italics in source]
The Art of Computer Programming (1968–2011)

AI Podcast, December 30, 2019, Algorithms, Complexity, Life, and The Art of Computer Programming https://www.youtube.com/watch?v=2BdBfsXbST8,