Update citation information

Update citation information in the dataset card.

README.md

@@ -1322,11 +1322,26 @@ The dataset, which contains paragraphs from Wikipedia, is licensed under CC-BY-S
 ### Citation Information
 
 ```
-@article{hardalov2020exams,
-  title={EXAMS: A Multi-subject High School Examinations Dataset for Cross-lingual and Multilingual Question Answering},
-  author={Hardalov, Momchil and Mihaylov, Todor and Dimitrina Zlatkova and Yoan Dinkov and Ivan Koychev and Preslav Nvakov},
-  journal={arXiv preprint arXiv:2011.03080},
-  year={2020}
+@inproceedings{hardalov-etal-2020-exams,
+    title = "{EXAMS}: A Multi-subject High School Examinations Dataset for Cross-lingual and Multilingual Question Answering",
+    author = "Hardalov, Momchil  and
+      Mihaylov, Todor  and
+      Zlatkova, Dimitrina  and
+      Dinkov, Yoan  and
+      Koychev, Ivan  and
+      Nakov, Preslav",
+    editor = "Webber, Bonnie  and
+      Cohn, Trevor  and
+      He, Yulan  and
+      Liu, Yang",
+    booktitle = "Proceedings of the 2020 Conference on Empirical Methods in Natural Language Processing (EMNLP)",
+    month = nov,
+    year = "2020",
+    address = "Online",
+    publisher = "Association for Computational Linguistics",
+    url = "https://aclanthology.org/2020.emnlp-main.438",
+    doi = "10.18653/v1/2020.emnlp-main.438",
+    pages = "5427--5444",
 }
 ```