1 files changed, 2 insertions, 2 deletions
diff --git a/ref.bib b/ref.bib
index 1fac4fb..1a39582 100644
--- a/ref.bib
+++ b/ref.bib
@@ -71,7 +71,7 @@ MRREVIEWER = {Manfred Wolff},
  PUBLISHER = {B. G. Teubner, Stuttgart},
       YEAR = {2006},
 %     PAGES = {696},
-      ISBN = {978-3-8351-0026-8; 3-8351-0026-2},
+      ISBN = {978-3-8351-0026-8},
    MRCLASS = {46-01 (47-01)},
   MRNUMBER = {2380292},
        URL = {https://doi.org/10.1007/978-3-8351-9072-6},
@@ -154,7 +154,7 @@ MRREVIEWER = {Jean Mawhin},
 @book{dobrowolski2010angewandte,
   title={Angewandte Funktionalanalysis: Funktionalanalysis, Sobolev-R{\"a}ume und elliptische Differentialgleichungen},
   author={Dobrowolski, M.},
-  isbn={9783642152696},
+  isbn={978-3-6421-5269-6},
   series={Springer-Lehrbuch Masterclass},
   year={2010},
   publisher={Springer Berlin Heidelberg}