There are many language models being developed by large companies and research groups. Most of these function similarly. We will look at a select few only. As before, this is a lot to read, so papers are mainly included as a reference.
There is a HUGE overview paper with A Survey of Large Language Models.
GPT series of papers:
As these are all developed by OpenAI, you could also check PaLM by Google.
Finally, a very important piece of research, providing justification for this research agenda, is Scaling Laws for Neural Language Models.
An important technique in fine-tuning LLMs, especially for human interaction.