|Authors:||Thom, Alexander; Stevenson Thom, Archibald; Strang Thom, Alexander|
|Publication:||Journal for the History of Astronomy, Vol. 5, p.71|
This link gives me the whole article as a pdf
It includes several plans including this one of the Z and Y holes based on Atkinson's information, the distances are Thom's and to do with his Megalithic Yard theory.