Differential equation (English Wikipedia)

Wheeler, Gerard F.; Crummett, William P. (1987). "The Vibrating String Controversy". Am. J. Phys. 55 (1): 33–37. Bibcode:1987AmJPh..55...33W. doi:10.1119/1.15311.

archive.org (Global: 6^th place; English: 6^th place)

Fourier, Joseph (1822). Théorie analytique de la chaleur (in French). Paris: Firmin Didot Père et Fils. OCLC 2688081.

books.google.com (Global: 3^rd place; English: 3^rd place)

Dennis G. Zill (15 March 2012). A First Course in Differential Equations with Modeling Applications. Cengage Learning. ISBN 978-1-285-40110-2.
For Lagrange's contributions to the acoustic wave equation, consult Acoustics: An Introduction to Its Physical Principles and Applications Allan D. Pierce, Acoustical Soc of America, 1989; page 18.(retrieved 9 Dec 2012)
Speiser, David. Discovering the Principles of Mechanics 1600-1800, p. 191 (Basel: Birkhäuser, 2008).
Elias Loomis (1887). Elements of the Differential and Integral Calculus (revised ed.). Harper & Bros. p. 247. Extract of page 247

doi.org (Global: 2^nd place; English: 2^nd place)

Wheeler, Gerard F.; Crummett, William P. (1987). "The Vibrating String Controversy". Am. J. Phys. 55 (1): 33–37. Bibcode:1987AmJPh..55...33W. doi:10.1119/1.15311.

lynge.com (Global: low place; English: low place)

For a special collection of the 9 groundbreaking papers by the three authors, see First Appearance of the wave equation: D'Alembert, Leonhard Euler, Daniel Bernoulli. - the controversy about vibrating strings Archived 2020-02-09 at the Wayback Machine (retrieved 13 Nov 2012). Herman HJ Lynge and Son.

maplesoft.com (Global: low place; English: low place)

"dsolve - Maple Programming Help". www.maplesoft.com. Retrieved 2020-05-09.

sagemath.org (Global: low place; English: low place)

doc.sagemath.org

"Basic Algebra and Calculus — Sage Tutorial v9.0". doc.sagemath.org. Retrieved 2020-05-09.

sourceforge.io (Global: low place; English: low place)

maxima.sourceforge.io

Schelter, William F. Gaertner, Boris (ed.). "Differential Equations - Symbolic Solutions". The Computer Algebra Program Maxima - a Tutorial (in Maxima documentation on SourceForge). Archived from the original on 2022-10-04.

sympy.org (Global: low place; English: low place)

docs.sympy.org

"ODE". SymPy 1.11 documentation. 2022-08-22. Archived from the original on 2022-09-26.

ujf-grenoble.fr (Global: low place; English: low place)

www-fourier.ujf-grenoble.fr

"Symbolic algebra and Mathematics with Xcas" (PDF).

utoronto.ca (Global: 1,483^rd place; English: 930^th place)

homes.chass.utoronto.ca

Frasier, Craig (July 1983). "Review of The evolution of dynamics, vibration theory from 1687 to 1742, by John T. Cannon and Sigalia Dostrovsky" (PDF). Bulletin of the American Mathematical Society. New Series. 9 (1).

web.archive.org (Global: 1^st place; English: 1^st place)

For a special collection of the 9 groundbreaking papers by the three authors, see First Appearance of the wave equation: D'Alembert, Leonhard Euler, Daniel Bernoulli. - the controversy about vibrating strings Archived 2020-02-09 at the Wayback Machine (retrieved 13 Nov 2012). Herman HJ Lynge and Son.
Order and degree of a differential equation, accessed Dec 2015.
Schelter, William F. Gaertner, Boris (ed.). "Differential Equations - Symbolic Solutions". The Computer Algebra Program Maxima - a Tutorial (in Maxima documentation on SourceForge). Archived from the original on 2022-10-04.
"ODE". SymPy 1.11 documentation. 2022-08-22. Archived from the original on 2022-09-26.

wolfram.com (Global: 1,091^st place; English: 1,169^th place)

mathworld.wolfram.com

Weisstein, Eric W. "Ordinary Differential Equation Order." From MathWorld--A Wolfram Web Resource. http://mathworld.wolfram.com/OrdinaryDifferentialEquationOrder.html

reference.wolfram.com

"DSolve - Wolfram Language Documentation". www.wolfram.com. Retrieved 2020-06-28.

worldcat.org (Global: 4^th place; English: 4^th place)

search.worldcat.org

Fourier, Joseph (1822). Théorie analytique de la chaleur (in French). Paris: Firmin Didot Père et Fils. OCLC 2688081.

Differential equation (English Wikipedia)

adsabs.harvard.edu (Global: 14th place; English: 9th place)

ui.adsabs.harvard.edu

archive.org (Global: 6th place; English: 6th place)

books.google.com (Global: 3rd place; English: 3rd place)

doi.org (Global: 2nd place; English: 2nd place)

lynge.com (Global: low place; English: low place)

maplesoft.com (Global: low place; English: low place)

sagemath.org (Global: low place; English: low place)

doc.sagemath.org

sourceforge.io (Global: low place; English: low place)

maxima.sourceforge.io

sympy.org (Global: low place; English: low place)

docs.sympy.org

ujf-grenoble.fr (Global: low place; English: low place)

www-fourier.ujf-grenoble.fr

utoronto.ca (Global: 1,483rd place; English: 930th place)

homes.chass.utoronto.ca

web.archive.org (Global: 1st place; English: 1st place)

wolfram.com (Global: 1,091st place; English: 1,169th place)

mathworld.wolfram.com

reference.wolfram.com

worldcat.org (Global: 4th place; English: 4th place)

search.worldcat.org

adsabs.harvard.edu (Global: 14^th place; English: 9^th place)

archive.org (Global: 6^th place; English: 6^th place)

books.google.com (Global: 3^rd place; English: 3^rd place)

doi.org (Global: 2^nd place; English: 2^nd place)

utoronto.ca (Global: 1,483^rd place; English: 930^th place)

web.archive.org (Global: 1^st place; English: 1^st place)

wolfram.com (Global: 1,091^st place; English: 1,169^th place)

worldcat.org (Global: 4^th place; English: 4^th place)