https://ctan.org/ctan-ann/pkg/diffcoeff
CTAN: CTAN-ann - diffcoeff
ctanann
https://ctan.math.washington.edu/tex-archive/macros/latex/contrib/diffcoeff/
Index of /tex-archive/macros/latex/contrib/diffcoeff
index oftexarchivemacroscontrib
https://ctan.org/ctan-ann/id/aPM7h3s52Ue8NFqZ@prptp?lang=en
CTAN: CTAN-ann - CTAN update: diffcoeff
ctanannupdate
https://www.ctan.org/pkg/diffcoeff
CTAN: Package diffcoeff
ctanpackage