diff --git a/paper.bib b/paper.bib
index cc1ed5c..5258ce4 100644
--- a/paper.bib
+++ b/paper.bib
@@ -5,7 +5,8 @@ @article{belanger2016
   volume={134},
   pages={95--105},
   year={2016},
-  publisher={Elsevier}
+  publisher={Elsevier},
+  doi={10.1016/j.ecoenv.2016.08.023}
 }
 
 @article{efsa2013,
@@ -16,7 +17,8 @@ @article{efsa2013
   number={7},
   pages={3290},
   year={2013},
-  publisher={Wiley Online Library}
+  publisher={Wiley Online Library},
+  doi={10.2903/j.efsa.2013.3290}
 }
 
 @article{newman2000,
@@ -27,14 +29,16 @@ @article{newman2000
   number={2},
   pages={508--515},
   year={2000},
-  publisher={Wiley Online Library}
+  publisher={Wiley Online Library},
+  doi={10.1002/etc.5620190233}
 }
 
 @book{posthuma2001,
   title={Species sensitivity distributions in ecotoxicology},
   author={Posthuma, Leo and Suter II, Glenn W and Traas, Theo P},
   year={2001},
-  publisher={CRC press}
+  publisher={CRC press},
+  doi={10.1201/9781420032314}
 }
 
 @article{wheeler2002,
@@ -45,7 +49,8 @@ @article{wheeler2002
   number={1-12},
   pages={192--202},
   year={2002},
-  publisher={Elsevier}
+  publisher={Elsevier},
+  doi={10.1002/etc.5620190233}
 }