Update README.md

README.md

@@ -71,7 +71,7 @@
 | 2022-09 |       Sparrow       |     DeepMind     | [Improving alignment of dialogue agents via targeted human judgements](https://arxiv.org/pdf/2209.14375.pdf)                                                                           |            |
 | 2022-10 |       Flan-T5/PaLM       |      Google      | [Scaling Instruction-Finetuned Language Models](https://arxiv.org/pdf/2210.11416.pdf)                                                                                                  |            |
 | 2022-10 |       GLM-130B       |     Tsinghua     | [GLM-130B: An Open Bilingual Pre-trained Model](https://arxiv.org/pdf/2210.02414.pdf)                                                                                                  |    ICLR    |
-| 2022-11 |         HELM         |     Stanford     | [Holistic Evaluation of Language Models](https://arxiv.org/pdf/2211.09110.pdf)                                                                                                         |            |
+| 2022-11 |         HELM         |     Stanford     | [Holistic Evaluation of Language Models](https://arxiv.org/pdf/2211.09110.pdf)                                                                                                                   |
 | 2022-11 |        BLOOM        |    BigScience    | [BLOOM: A 176B-Parameter Open-Access Multilingual Language Model](https://arxiv.org/pdf/2211.05100.pdf)                                                                                |            |
 | 2022-11 |      Galactica      |       Meta       | [Galactica: A Large Language Model for Science](https://arxiv.org/pdf/2211.09085.pdf)                                                                                                  |            |
 | 2022-12 | OPT-IML |  Meta | [OPT-IML: Scaling Language Model Instruction Meta Learning through the Lens of Generalization](https://arxiv.org/pdf/2212.12017)  |            |
@@ -84,6 +84,7 @@
 | 2023-05 | Dromedary | CMU et al. | [Principle-Driven Self-Alignment of Language Models from Scratch with Minimal Human Supervision](https://arxiv.org/abs/2305.03047)||
 | 2023-05 | PaLM 2 | Google | [PaLM 2 Technical Report](https://ai.google/static/documents/palm2techreport.pdf)||
 | 2023-05 | RWKV | Bo Peng | [RWKV: Reinventing RNNs for the Transformer Era](https://arxiv.org/abs/2305.13048) ||
+| 2022-05 | Direct Preference Optimization | Stanford | [Direct Preference Optimization: Your Language Model is Secretly a Reward Model](https://arxiv.org/pdf/2305.18290.pdf) ||