diff --git a/readme.md b/readme.md
index df9543b..b6b9667 100755
--- a/readme.md
+++ b/readme.md
@@ -22,6 +22,7 @@
 		- [Hierarchical SfM](#papers-sfm-hierarchical)
 		- [Multi-Stage SfM](#papers-sfm-multi-stage)
 		- [Non Rigid SfM](#papers-non-rigid-sfm)
+		- [Constrained SfM](#papers-constrained-sfm)
 <br/><br/>
 		- [Viewing graph optimization](#papers-sfm-graph)
 		- [Unordered feature tracking](#papers-sfm-tracking)
@@ -174,6 +175,14 @@ R. Shah, A. Deshpande, P. J. Narayanan. 3DV 2014. -> [Multistage SFM: A Coarse-t
 
 [Robust Structure from Motion in the Presence of Outliers and Missing Data](http://arxiv.org/abs/1609.02638). G. Wang, J. S. Zelek, J. Wu, R. Bajcsy. 2016.
 
+
+
+<a name="papers-constrained-sfm"></a>
+### Constrained SfM
+[Symmetric Non-Rigid Structure from Motion for Category-Specific Object Structure Estimation](https://arxiv.org/abs/1609.06988). Y. Gao, A. Yuille. ECCV 2016.
+
+[Exploiting Symmetry and/or Manhattan Properties for 3D Object Structure Estimation from Single and Multiple Images](https://arxiv.org/abs/1607.07129). Y. Gao, A. Yuille, CVPR 2017.
+
 <a name="papers-sfm-graph"></a>
 ### Viewing graph optimization