def get_bibtex(model_identifier):
    """
    A method returning the bibtex reference of the requested model as a string.
    """
    return """
    @article{https://doi.org/10.48550/arxiv.2203.12601,
      doi = {10.48550/ARXIV.2203.12601},
      url = {https://arxiv.org/abs/2203.12601},
      author = {Nair, Suraj and Rajeswaran, Aravind and Kumar, Vikash and Finn, Chelsea and Gupta, Abhinav},
      keywords = {Robotics (cs.RO), Artificial Intelligence (cs.AI), Computer Vision and Pattern Recognition (cs.CV), Machine Learning (cs.LG), FOS: Computer and information sciences, FOS: Computer and information sciences},
      title = {R3M: A Universal Visual Representation for Robot Manipulation},
      publisher = {arXiv},
      year = {2022},
      copyright = {arXiv.org perpetual, non-exclusive license}
    }"""