diff --git a/cs/literatura.bib b/cs/literatura.bib
index a03ae76..402ebff 100644
--- a/cs/literatura.bib
+++ b/cs/literatura.bib
@@ -39,7 +39,7 @@
   journal = {Journal of the Royal Statistical Society, Series B},
   year = {1972},
   volume = {34},
-  pages = {187-220},
+  pages = {187--220},
   number = {2}
 }
 
@@ -49,7 +49,7 @@
   journal = {Journal of the Royal Statistical Society, Series B},
   year = {1977},
   volume = {39},
-  pages = {1-38},
+  pages = {1--38},
   number = {1}
 }
 
@@ -62,7 +62,7 @@
   journal = {Journal of Acquired Immune Deficiency Syndrome},
   year = {2008},
   volume = {49},
-  pages = {309-319}
+  pages = {309--319}
 }
 
 @ARTICLE{KaplanMeier58,
@@ -71,7 +71,7 @@
   journal = {Journal of the American Statistical Association},
   year = {1958},
   volume = {53},
-  pages = {457-481},
+  pages = {457--481},
   number = {282}
 }