硬筆尖 (Chinese Wikipedia)

Where's the Iridium?. The Nibster. [26 July 2016]. （原始内容存档于2016-08-01）.
Mottishaw, J. How can we talk about Iridium?. The PENnant. 1999, XIII (2) [2019-07-09]. （原始内容存档于2016-12-05）.

penheaven.co.uk

Steel vs. Gold Fountain Pen Nibs. Pen Heaven. [26 July 2016]. （原始内容存档于2020-11-24）.

richardspens.com

Binder, Richard. To the Point: Nib Materials. Richard Binder's Pens. [26 July 2016]. （原始内容存档于2021-04-27）.
Binder, Richard. Filling Systems: Overview of How They Work and How to Fill Them. Richard Binder's Pens. [26 July 2016]. （原始内容存档于2021-04-27）.
Binder, Richard. To the Point: Making Music with a Pen. Richard Binder's Pens. [26 July 2016]. （原始内容存档于2021-04-27）.
Binder, Richard. Nibs I: The Basics. Richard Binder's Pens. [26 July 2016]. （原始内容存档于2021-04-27）.
Binder, Richard. Nibs II: Beyond the Basics with Specialty Nibs. Richard Binder's Pens. [26 July 2016]. （原始内容存档于2021-04-28）.
Binder, Richard. Rethinking The Value of Steel Nibs. Richard Binder's Pens. [27 July 2016]. （原始内容存档于2021-04-26）.
Binder, Richard. To the Point: Steal the Steel. Richard Binder's Pens. [26 July 2016]. （原始内容存档于2021-10-10）.

theesterbrookproject.com

Esterbrook # 312 Judge's Quill. The Esterbrook Project. [2019-07-09]. （原始内容存档于2020-10-03）.
Esterbrook # 313 Probate Pen. The Esterbrook Project. [2019-07-09]. （原始内容存档于2020-02-24）.
Esterbrook #339z 律师笔. The Esterbrook Project. [2019-07-09]. （原始内容存档于2020-10-03）.

theparisreview.org

Piepenbring, Dan. Tools of the Trade. The Paris Review. November 17, 2014 [2019-07-09]. （原始内容存档于2021-04-27）.

thesteelpen.com

笔的历史：最原始的笔和钢笔. The Steel Pen. （原始内容存档于2020-11-28）.
早期金属笔的其他证据. The Steel Pen: Writing, History and the History of How we Write. （原始内容存档于2021-02-26）.
Peregrine Williamson: Inventor, Businessman, and Pioneer Pen Maker. The Steel Pen. （原始内容存档于2021-01-25）.
笔的历史: 早年 – 1820年代. The Steel Pen. （原始内容存档于2021-04-27）.
笔的历史: 早年 – 1830年代. The Steel Pen. （原始内容存档于2021-01-18）.
存档副本. [2019-07-09]. （原始内容存档于2018-07-11）.

vintagepen.net

Grading Flex Nibs. VintagePen. [26 July 2016]. （原始内容存档于2021-04-27）.

web.archive.org

羽毛笔（页面存档备份，存于互联网档案馆）的起源
"历史 101: 钢笔和墨水" （页面存档备份，存于互联网档案馆）, Daily Kos，2013.11.16
笔的历史：最原始的笔和钢笔. The Steel Pen. （原始内容存档于2020-11-28）.
早期金属笔的其他证据. The Steel Pen: Writing, History and the History of How we Write. （原始内容存档于2021-02-26）.
Peregrine Williamson: Inventor, Businessman, and Pioneer Pen Maker. The Steel Pen. （原始内容存档于2021-01-25）.
1809年为Wise和Willianmson制作的钢笔广告. 1809. （原始内容存档于2019-06-07）.
笔的历史: 早年 – 1820年代. The Steel Pen. （原始内容存档于2021-04-27）.
笔的历史: 早年 – 1830年代. The Steel Pen. （原始内容存档于2021-01-18）.
存档副本. [2019-07-09]. （原始内容存档于2018-07-11）.
Esterbrook # 312 Judge's Quill. The Esterbrook Project. [2019-07-09]. （原始内容存档于2020-10-03）.
Esterbrook # 313 Probate Pen. The Esterbrook Project. [2019-07-09]. （原始内容存档于2020-02-24）.
Esterbrook #339z 律师笔. The Esterbrook Project. [2019-07-09]. （原始内容存档于2020-10-03）.
Piepenbring, Dan. Tools of the Trade. The Paris Review. November 17, 2014 [2019-07-09]. （原始内容存档于2021-04-27）.
Mathur, P.; Mathur, K.; Mathur, S. Developments and Changes in Science Based Technologies. : 128 [2019-07-09]. ISBN 1-4828-1398-X. （原始内容存档于2020-08-01）.
Binder, Richard. To the Point: Nib Materials. Richard Binder's Pens. [26 July 2016]. （原始内容存档于2021-04-27）.
Steel vs. Gold Fountain Pen Nibs. Pen Heaven. [26 July 2016]. （原始内容存档于2020-11-24）.
Where's the Iridium?. The Nibster. [26 July 2016]. （原始内容存档于2016-08-01）.
Mottishaw, J. How can we talk about Iridium?. The PENnant. 1999, XIII (2) [2019-07-09]. （原始内容存档于2016-12-05）.
Binder, Richard. Filling Systems: Overview of How They Work and How to Fill Them. Richard Binder's Pens. [26 July 2016]. （原始内容存档于2021-04-27）.
How Fountain Pens Work. Explain That Stuff. [27 July 2016]. （原始内容存档于2021-04-25）.
Binder, Richard. To the Point: Making Music with a Pen. Richard Binder's Pens. [26 July 2016]. （原始内容存档于2021-04-27）.
Binder, Richard. Nibs I: The Basics. Richard Binder's Pens. [26 July 2016]. （原始内容存档于2021-04-27）.
Binder, Richard. Nibs II: Beyond the Basics with Specialty Nibs. Richard Binder's Pens. [26 July 2016]. （原始内容存档于2021-04-28）.
Grading Flex Nibs. VintagePen. [26 July 2016]. （原始内容存档于2021-04-27）.
Binder, Richard. Rethinking The Value of Steel Nibs. Richard Binder's Pens. [27 July 2016]. （原始内容存档于2021-04-26）.
Fountain Pen Guide. Gentleman's Gazette. [27 July 2016]. （原始内容存档于2020-11-12）.
Binder, Richard. To the Point: Steal the Steel. Richard Binder's Pens. [26 July 2016]. （原始内容存档于2021-10-10）.
How to Collect and Buy Vintage Fountain Pens. The Art of Manliness. 19 November 2015 [27 July 2016]. （原始内容存档于2018-03-12）.