diff --git a/spras/rwr.py b/spras/rwr.py
index e7691f16..759df0e4 100644
--- a/spras/rwr.py
+++ b/spras/rwr.py
@@ -16,7 +16,9 @@
 
 class RWR(PRM):
     required_inputs = ['network','nodes']
-    dois = []
+    # Paper relevant to biological applications of random walks,
+    # then the original personalized PageRank paper.
+    dois = ["10.1093/bioinformatics/btq680", "10.1145/511446.511513"]
 
     @staticmethod
     def generate_inputs(data, filename_map):
diff --git a/spras/strwr.py b/spras/strwr.py
index c99b3983..e94102b8 100644
--- a/spras/strwr.py
+++ b/spras/strwr.py
@@ -15,7 +15,9 @@
 # Note: This class is almost identical to the rwr.py file.
 class ST_RWR(PRM):
     required_inputs = ['network','sources','targets']
-    dois = []
+    # Paper relevant to biological applications of random walks,
+    # then the personalization-vector-based PageRank paper.
+    dois = ["10.1093/bioinformatics/btq680", "10.1145/511446.511513"]
 
     @staticmethod
     def generate_inputs(data, filename_map):