intent to add

README.md

@@ -493,6 +493,14 @@ img = torch.randn(1, 3, 224, 224)
 pred = model(img) # (1, 1000)
 ```
 
+## CrossFormer (wip)
+
+<img src="./images/crossformer.png" width="400px"></img>
+
+This <a href="https://arxiv.org/abs/2108.00154">paper</a> beats PVT and Swin using alternating local and global attention. The global attention is done across the windowing dimension for reduced complexity, much like the scheme used for axial attention.
+
+They also have cross-scale embedding layer, which they shown to be a generic layer that can improve all vision transformers. Dynamic relative positional bias was also formulated to allow the net to generalize to images of greater resolution.
+
 ## NesT
 
 <img src="./images/nest.png" width="400px"></img>
@@ -1045,6 +1053,17 @@ Coming from computer vision and new to transformers? Here are some resources tha
 }
 ```
 
+```bibtex
+@misc{wang2021crossformer,
+    title   = {CrossFormer: A Versatile Vision Transformer Hinging on Cross-scale Attention}, 
+    author  = {Wenxiao Wang and Lu Yao and Long Chen and Binbin Lin and Deng Cai and Xiaofei He and Wei Liu},
+    year    = {2021},
+    eprint  = {2108.00154},
+    archivePrefix = {arXiv},
+    primaryClass = {cs.CV}
+}
+```
+
 ```bibtex
 @misc{caron2021emerging,
     title   = {Emerging Properties in Self-Supervised Vision Transformers},