Add missing doi to a reference

paper.bib

@@ -102,22 +102,15 @@ @article{Groen_multiscale_survey
 }
 
 @InProceedings{MUSCLE3,
-	author="Veen, Lourens E.
-	and Hoekstra, Alfons G.",
-	editor="Krzhizhanovskaya, Valeria V.
-	and Z{\'a}vodszky, G{\'a}bor
-	and Lees, Michael H.
-	and Dongarra, Jack J.
-	and Sloot, Peter M. A.
-	and Brissos, S{\'e}rgio
-	and Teixeira, Jo{\~a}o",
-	title="Easing Multiscale Model Design and Coupling with MUSCLE 3",
-	booktitle="Computational Science -- ICCS 2020",
-	year="2020",
-	publisher="Springer International Publishing",
-	address="Cham",
-	pages="425--438",
-	isbn="978-3-030-50433-5"
+	author={Veen, Lourens E. and Hoekstra, Alfons G.},
+	editor={Krzhizhanovskaya, Valeria V. and Z{\'a}vodszky, G{\'a}bor and Lees, Michael H. and Dongarra, Jack J. and Sloot, Peter M. A.	and Brissos, S{\'e}rgio and Teixeira, Jo{\~a}o},
+	title={Easing Multiscale Model Design and Coupling with MUSCLE 3},
+	booktitle={Computational Science -- ICCS 2020},
+	year={2020},
+	publisher={Springer International Publishing},
+	address={Cham},
+	pages={425--438},
+    doi = {10.1007/978-3-030-50433-5_33}
 }
 
 @article{MUI,