Understanding Source Localization of bst_inverse_linear[2018]

Hi Younes:
I have a similar problem with you,as show in
https://forum.bic.mni.mcgill.ca/t/brainstorm-tutorial-question/1246/2
The Brainstorm software provided wonderful tutorials for beginners, while, beautiful yet incomplete, there are not enough mathematical formulas for understanding it’s codes.
If you find papers corresponding to ‘bst_inverse_linear[2018]’, please share with me.
With Warm Regards
Ming