誰も + potential verb form


I'm pretty sure "誰にも読めない本" is correct. However, I have also heard something in
the same vein as "誰も読めない本", without the に. Is this also correct?  
If so, does も replace が here?




> 誰も読めない本, without the に. Is this also correct?

Yes, it is correct in this case.

> If so, does も replace が here?

No, it cannot be replaced. 誰も読めない本 is correct. 誰が読めない本 is incorrect. Japanese
people never say it like this.

