add HIP'23 paper reference

README.md

@@ -94,3 +94,18 @@ ocrd-eynollah-segment -I OCR-D-IMG-BIN -O SEG-LINE -P models
 ```
     
 uses the original (RGB) image despite any binarization that may have occured in previous OCR-D processing steps
+
+## How to cite
+If you find this tool useful in your work, please consider citing our paper:
+
+```
+@article{rezanezhad2023eynollah,
+  title = {Document Layout Analysis with Deep Learning and Heuristics},
+  author = {Rezanezhad, Vahid and Baierer, Konstantin and Gerber, Mike and Labusch, Kai and Neudecker, Clemens},
+  booktitle = {Proceedings of the 7th International Workshop on Historical Document Imaging and Processing {HIP} 2023,
+  San José, US, August 25-26, 2023, ACM.},
+  year = {2023},
+  url = {https://doi.org/10.1145/3604951.3605513}
+}
+```
+```