Most informative pick up theory book?

[8nexus8]

Hey everyone, new here.
As there's a lot of misinformation and "mysticism" regarding pick ups, I'm looking for the most informative and contemporary book about pick up theory to organize everything in my head.
I have a background in engineering so the more math, physics and technicality involved the better.

I have searched this forum a bit and heard names like Lemme Helmuth/Erno Zwaan/Dave Hunter/Mario Milan.

I have also already read Donald Brosnac's book and it was awesome.
So far I'm leaning towards Lemme's book as I heard it's the most in depth and technical.
Thanks!

[Helmholtz]

I do recommend Helmuth Lemme's books.
But the most comprehensive and scientific PU theory resource is electroacoustics professor Manfred Zollner's book "Physik der Elektogitarre". Nothing else comes close.
A lot of good PU/ theory discussion here: https://guitarnuts2.proboards.com/board/16/pickups.