GPT
Improving language understanding by generative pre-training
https://www.mikecaptain.com/resources/pdf/GPT-1.pdf
GPT-1, cited 15k, published in 2018
Language Models are Unsupervised Multitask Learners
Cited 18k, published in 2019
It is GPT-2. Code: https://github.com/openai/gpt-2