III. Image credit: Arpad Horvath (16 March 2006, see http://en.wikipedia.org/wiki/File:Quark_structure_pion.svg (source)), adapted by Eternus (4 April 2015): aligning / changing places of some elements, change of font. This work is licensed under a Creative Commons Attribution-Share Alike 2.5 Generic license (for details, please visit https://creativecommons.org/licenses/by-sa/2.5/ (about this license)).

IV. Image credit: Roshan220195 (29 June 2012, see http://en.wikipedia.org/wiki/File:Periodic_Table_2.svg (source)), modified by Eternus (4 April 2015): removing last three periods of table, adding bottom border, aligning / changing places of some elements, changing design of arrows, change of font. This work is licensed under a Creative Commons Attribution-Share Alike 3.0 Unported license (for details, please visit https://creativecommons.org/licenses/by-sa/3.0/ (about this license)).

V. Left image credit: Tomruen (9 October 2010, see http://en.wikipedia.org/wiki/File:3-cube_t1.svg (source)), changed by Eternus (9 April 2015): rotated, central point added. This work is in the public domain.

VI. Right image credit: Tomruen (26 April 2011, see http://commons.wikimedia.org/wiki/File:Icosahedron_t0_A2.png (source)), modified by Eternus (5 December 2015): cropped, central point added. This work is in the public domain.

VII. Image by P.wormer (6 December 2010, see https://commons.wikimedia.org/wiki/File:Representative-spherical_harmonics.png (source)). This work is licensed under a Creative Commons Attribution-Share Alike 3.0 Unported license (for details, please visit https://creativecommons.org/licenses/by-sa/3.0/ (about this license)).

VIII. Image credit: FlorianMarquardt (14 Oct 2002), with modification (4 July 2009, see https://en.wikipedia.org/wiki/File:HAtomOrbitals.png (source)) by Falcorian. This work is licensed under a Creative Commons Attribution-Share Alike 3.0 Unported license (for details, please visit https://creativecommons.org/licenses/by-sa/3.0/ (about this license)).

IX. Frames, extracted by Eternus (2015), from file Drum vibration mode01.gif. Original file — by Oleg Alexandrov (16 January 2008, see http://en.wikipedia.org/wiki/File:Drum_vibration_mode01.gif (source)). This work is in the public domain.

X. Frames, extracted by Eternus (2015), from file Drum_vibration_mode02.gif. Original file — by Oleg Alexandrov (16 January 2008, see http://en.wikipedia.org/wiki/File:Drum_vibration_mode02.gif (source)). This work is in the public domain.

XI. Frames, extracted by Eternus (2015), from file Drum_vibration_mode03.gif. Original file — by Oleg Alexandrov (8 June 2008, see http://en.wikipedia.org/wiki/File:Drum_vibration_mode03.gif (source)). This work is in the public domain.

XII. Left image credit: Dhatfield (25 September 2008). This work is in the public domain. Source: http://en.wikipedia.org/wiki/File:P2M0.png

XIII. Central image credit: Dhatfield (25 September 2008). This work is in the public domain. Source: http://en.wikipedia.org/wiki/File:P2M1.png

XIV. Right image credit: Dhatfield (25 September 2008). This work is in the public domain. Source: http://en.wikipedia.org/wiki/File:P2M-1.png

XV. Image credit: Sven (30 June 2006, see http://en.wikipedia.org/wiki/File:D_orbitals.svg (source)), modified by Eternus (4 December 2015): cropped, change of font. This work is licensed under a Creative Commons Attribution-Share Alike 3.0 Unported license (for details, please visit https://creativecommons.org/licenses/by-sa/3.0/ (about this license)).

XVI. Frames, extracted from file Drum_vibration_mode11.gif and cropped by Eternus (2015). Original file — by Oleg Alexandrov (16 January 2008, see http://en.wikipedia.org/wiki/File:Drum_vibration_mode11.gif (source)). This work is in the public domain.

XVII. Frames, extracted from file Drum_vibration_mode12.gif and cropped by Eternus (2015). Original file — by Oleg Alexandrov (12 January 2008, see http://en.wikipedia.org/wiki/File:Drum_vibration_mode12.gif (source)). This work is in the public domain.

XVIII. Frames, extracted from file Drum_vibration_mode21.gif and cropped by Eternus (2015). Original file — by Oleg Alexandrov (12 January 2008, see http://en.wikipedia.org/wiki/File:Drum_vibration_mode21.gif (source)). This work is in the public domain.

XIX. Image credit: Patricia.fidi (27 December 2006), with modifications (latest — 6 July 2012, see http://en.wikipedia.org/wiki/File:Electron_orbitals.svg (source)) by Mathieu Perrin, Quibik, Quaerendo, changed by Eternus (9 December 2015): cropping, aligning / changing places of some elements, dividing line added, change of font, cleaning of code. This work is in the public domain.

XX. Автор изображения: Tigran Mitr am (13 октября 2008, см. http://ru.wikipedia.org/wiki/%D0%A4%D0%B0%D0%B9%D0%BB:%D0%AD%D0%BB%D0%B5%D0%BA%D1%82%D1%80%D0%BE%D0%BE%D1%82%D1%80%D0%B8%D1%86%D0%B0%D1%82%D0%B5%D0%BB%D1%8C%D0%BD%D0%BE%D1%81%D1%82%D1%8C.jpg (источник)). Рис. передан в общественное достояние.

XXI. Image credit: StringTheory11 (2012), with modifications (latest — 18 August 2014, see http://en.wikipedia.org/wiki/File:Empirical_atomic_radius_trends.png (source)) by Soerfm, Quenhitran, changed by Eternus (2015): cropping. This work is licensed under a Creative Commons Attribution-Share Alike 4.0 International license (for details, please visit https://creativecommons.org/licenses/by-sa/4.0/ (about this license)), 3.0 Unported license (for details, please visit https://creativecommons.org/licenses/by-sa/3.0/ (about this license)), 2.5 Generic license (for details, please visit https://creativecommons.org/licenses/by-sa/2.5/ (about this license)), 2.0 Generic license (for details, please visit https://creativecommons.org/licenses/by-sa/2.0/ (about this license)) and 1.0 Generic license (for details, please visit https://creativecommons.org/licenses/by-sa/1.0/ (about this license)).