William the Silent (English Wikipedia)

Abelous, Louis David (1872). William the Taciturn. Translated by Lacroix, J. P. The Library of Congress catalogued with subject "William I, Prince of Orange (1534–1584). New York: Nelson & Phillips; [etc.]
Wedgwood, C.V. (1944). William the Silent. Jonathan Cape. pp. 235.
Rowen, Herbert H. (1988). The princes of Orange: the stadholders in the Dutch Republic. Cambridge University Press. p. 29. ISBN 9780521345255.

books.google.com

Midelfort, H. C. Erik (1994). Mad Princes of Renaissance Germany. Virginia, United States: University of Virginia Press (published 22 January 1996). p. 58. ISBN 978-0-8139-1501-2.

J. Thorold Rogers, The Story of Nations: Holland. London, 1889; Romein, J., and Romein-Verschoor, A. Erflaters van onze beschaving. Amsterdam 1938–1940, p. 150. (Dutch, at DBNL.org).
Fruin, Robert (1903). "Verspreide geschriften. Deel 8. Kritische studiën over geschiedbronnen. Deel 2. Historische schetsen en boekbeoordeelingen. Deel 1. 'Willem de Zwijger (1864)'". DBNL Digitale bibiotheek voor de Nederlandse letteren (in Dutch). pp. 404–407. Retrieved 28 December 2022.
Schaper, Bertus Willem (1954–1955). "Het werkende woord. Het Adagium van Willem de Zwijger" [The working word. The Adage of William the Silent]. Maatstaf: Maandblad voor letteren (in Dutch). 2: 24–31. Retrieved 8 May 2022.
"Justinus of Nassau is the son, probably born in September 1559, of the Prince and Eva Elinx, who, according to some, was the daughter of a mayor of Emmerich." (Adriaen Valerius, Nederlandtsche gedenck-clanck. P.J. Meertens, N.B. Tenhaeff and A. Komter-Kuipers (eds.). Wereldbibliotheek, Amsterdam 1942; p. 148, note. (Dutch, on DBNL)).

Motley, John Lothrop (1885). The Rise of the Dutch Republic. Vol. I. Harper Brothers. As Philip was proceeding on board the ship which was to bear him forever from the Netherlands, his eyes lighted upon the Prince. His displeasure could no longer be restrained. With angry face he turned upon him, and bitterly reproached him for having thwarted all his plans by means of his secret intrigues. William replied with humility that every thing which had taken place had been done through the regular and natural movements of the states. Upon this the King, boiling with rage, seized the Prince by the wrist, and shaking it violently, exclaimed in Spanish, "No los estados, ma vos, vos, vos!—Not the estates, but you, you, you!" repeating thrice the word vos, which is as disrespectful and uncourteous in Spanish as "toi" in French.
Motley, John L. (1856). The Rise of the Dutch Republic, Vol. 3.

"...our son Justin van Nassau" in letter from William of Orange to Diederik Sonoy dated 16 July 1582, facsimile at Inghist.nl

"den swijger", "den Schweiger": Emanuel van Meteren, 1608 and 1614; cf. "Taciturnus": Famiano Strada, 1635. The Dutch historian Robert Fruin (1864) has argued that this is in fact an erroneous rendering of the phrase "astutus Gulielmus", "cunning William", found in a Latin source of 1574 and attributed there to the Flemish inquisitor Pieter Titelmans. See Leiden University, De Tachtigjarige Oorlog. Willem de Zwijger.

"Hoe wordt Willem van Oranje vader des vaderlands?". NPO Kennis (in Dutch). Retrieved 5 October 2021.

John Whitehead Historian, Oxford, Oriel College, weblog page about William I Once I was a clever boy

"Willie". Libraries: Special Collections and University Archives. Rutgers University. Archived from the original on 3 September 2006. Retrieved 23 April 2010.

For example: van der Merwe, Pieter Ben (2004). Mobile Commerce Over GSM: A Banking Perspective on Security (PDF). University of Pretoria. p. vii.

"Willie". Libraries: Special Collections and University Archives. Rutgers University. Archived from the original on 3 September 2006. Retrieved 23 April 2010.

J. Thorold Rogers, The Story of Nations: Holland. London, 1889; Romein, J., and Romein-Verschoor, A. Erflaters van onze beschaving. Amsterdam 1938–1940, p. 150. (Dutch, at DBNL.org).