fix: doi

DESCRIPTION

@@ -1,14 +1,14 @@
 Package: cfda
 Type: Package
 Title: Categorical Functional Data Analysis
-Version: 0.9.10
-Date: 2021-12-03
+Version: 0.9.11
+Date: 2021-12-07
 Authors@R: c(person("Cristian", "Preda", role = "aut", email = "[email protected]"),
              person("Quentin", "Grimonprez", role = c("aut", "cre"), email = "[email protected]"),
              person("Vincent", "Vandewalle", role = "ctb", email = "[email protected]"))
 Copyright: Inria - Université de Lille
 Description: Package for the analysis of categorical functional data. 
-  The main purpose is to compute an encoding (real functional variable) for each state <doi:10.1080/00031305.2017.1375990>. 
+  The main purpose is to compute an encoding (real functional variable) for each state <doi:10.3390/math9233074>. 
   It also provides functions to perform basic statistical analysis on categorical functional data. 
 BugReports: https://github.com/modal-inria/cfda/issues
 License: AGPL-3