['wikipedia', 'bookcorpus']
['pytorch', 'tf', 'bert', 'pretraining', 'en', 'dataset:wikipedia', 'dataset:bookcorpus', 'arxiv:2111.05754', 'arxiv:1810.04805', 'arxiv:1910.01108', 'transformers', 'fill-mask', 'license:apache-2.0']