update model card with citation

README.md

@@ -62,4 +62,13 @@ model = AutoModelForCausalLM.from_pretrained(model_id, load_in_8bit=True)
 
 If you use this model in your research, please cite the following:
 
-*Coming soon*!
+```bibtex
+@misc{basile2023llamantino,
+      title={LLaMAntino: LLaMA 2 Models for Effective Text Generation in Italian Language}, 
+      author={Pierpaolo Basile and Elio Musacchio and Marco Polignano and Lucia Siciliani and Giuseppe Fiameni and Giovanni Semeraro},
+      year={2023},
+      eprint={2312.09993},
+      archivePrefix={arXiv},
+      primaryClass={cs.CL}
+}
+```