Clinical Notes database for research

Question

My research is on extracting diagnoses from clinical notes/reports using Artificial Intelligence.

I am strugling with finding good datasets that has big number of records

I have MIMIC dataset but one dataset is not enough and need at least 4 datasets more.

I read in this research

https://bmcmedinformdecismak.biomedcentral.com/track/pdf/10.1186/s12911-017-0556-8.pdf

They used MGH dataset with more than 91,000 records

I tried to find this dataset but could not

I found another dataset called MGH Waveform but this is not mainly for clinical notes.

I tried to contact the author of this research to ask but no response.

I wonder if anyone can help me find big datasets for clinical notes.

Thanks