[antir-heralds] book reliability check

[James D Sena]

I was given two books on names, and was wondering about how reliable 
they are:

Book of Irish Names - First, Family and Place names - by Ronan Coghlan, 
Ida Grehan & P.W. Joyce
 

The Origin and Signification of Scottish Surnames - by Clifford Stanley Sims



I suspect neither is particularly useful, but input is always appreciated.

Brendan ap Llewelyn