diff --git a/torchreid/models/densenet.py b/torchreid/models/densenet.py
index 656d531..b23df33 100644
--- a/torchreid/models/densenet.py
+++ b/torchreid/models/densenet.py
@@ -55,7 +55,12 @@ class _Transition(nn.Sequential):
 
 
 class DenseNet(nn.Module):
-
+    """
+    Densely connected network
+    
+    Reference:
+    Huang et al. Densely Connected Convolutional Networks. CVPR 2017.
+    """
     def __init__(self, num_classes, loss, growth_rate=32, block_config=(6, 12, 24, 16),
                  num_init_features=64, bn_size=4, drop_rate=0, fc_dims=None, dropout_p=None, **kwargs):
 
diff --git a/torchreid/models/senet.py b/torchreid/models/senet.py
index af1db26..e879c85 100644
--- a/torchreid/models/senet.py
+++ b/torchreid/models/senet.py
@@ -211,7 +211,12 @@ class SEResNeXtBottleneck(Bottleneck):
 
 
 class SENet(nn.Module):
-
+    """
+    Squeeze-and-excitation network
+    
+    Reference:
+    Hu et al. Squeeze-and-Excitation Networks. CVPR 2018.
+    """
     def __init__(self, num_classes, loss, block, layers, groups, reduction, dropout_p=0.2,
                  inplanes=128, input_3x3=True, downsample_kernel_size=3, downsample_padding=1,
                  last_stride=2, fc_dims=None, **kwargs):