[paper] use new dumux ref

paper.bib

@@ -76,13 +76,14 @@ keywords = "Fracture networks, DFN, Stochastic modeling, Open source, Matlab, Fl
   Doi                      = {10.1016/j.advwatres.2011.03.007}
 }
 
-@Misc{koch2019dumux31,
-  author        = {Timo Koch and Dennis Gläser and Kilian Weishaupt and Sina Ackermann and Martin Beck and Beatrix Becker and Samuel Burbulla and Holger Class and Edward Coltman and Simon Emmert and Thomas Fetzer and Christoph Grüninger and Katharina Heck and Johannes Hommel and Theresa Kurz and Melanie Lipp and Farid Mohammadi and Samuel Scherrer and Martin Schneider and Gabriele Seitz and Leopold Stadler and Martin Utz and Felix Weinhardt and Bernd Flemisch},
-  title         = {DuMu$^\text{x}$ 3 -- an open-source simulator for solving flow and transport problems in porous media with a focus on model coupling},
-  year          = {2019},
-  archiveprefix = {arXiv},
-  eprint        = {1909.05052},
-  primaryclass  = {cs.CE},
+@Article{Kochetal2020Dumux,
+  author   = {Timo Koch and Dennis Gl\"aser and Kilian Weishaupt and Sina Ackermann and Martin Beck and Beatrix Becker and Samuel Burbulla and Holger Class and Edward Coltman and Simon Emmert and Thomas Fetzer and Christoph Gr\"uninger and Katharina Heck and Johannes Hommel and Theresa Kurz and Melanie Lipp and Farid Mohammadi and Samuel Scherrer and Martin Schneider and Gabriele Seitz and Leopold Stadler and Martin Utz and Felix Weinhardt and Bernd Flemisch},
+  title    = {{DuMu\textsuperscript{x} 3 - an open-source simulator for solving flow and transport problems in porous media with a focus on model coupling}},
+  journal  = {Computers \& Mathematics with Applications},
+  year     = {2020},
+  issn     = {0898-1221},
+  doi      = {10.1016/j.camwa.2020.02.012},
+  keywords = {Porous media, Multi-phase flow, , Coupled problems, Open-source software, Research software},
 }
 
 @Article{glaeser2017,

paper.md

@@ -118,7 +118,7 @@ of all geometric entities involved, i.e. the intersection geometries between
 all entities are computed. Thus, this information can be directly used in the
 context of discrete fracture-matrix (dfm) simulations in a conforming way as
 described before. For instance, the open-source simulator
-[DuMuX][3] [@Dumux; @koch2019dumux31]
+[DuMuX][3] [@Dumux; @Kochetal2020Dumux]
 contains a module for conforming dfm simulations of single- and multi-phase
 flow through fractured porous media, which has been used in several works
 [@glaeser2017; @glaeser2019; @andrianov2019].