If you're mathematically minded, there are a series of books on braiding by Schaake, Turner and Sedgwick from the department of mathematics and statistics at the University of Waikato.
In particular, "Book 4/1 - Braiding - Standard Herringbone Pineapple Knots" gives formulae for constructing any turks head, or combination/intertwining of turks heads. There's an example on the following page of my web site of 3 turks heads nested together (sorry, the photo isn't brilliant, but it'll suffice for now) -
http://www.gr8-knots.com/other_coverings.htmA word of warning ... although understanding the formulae does enable you to tie just about any turks head, it took me ages to get my head around this book - it's quite heavy duty. I don't regret perservering though.
I got the series of books from Des and Liz at Footrope Knots - I don't know if they still stock them. For your info, the ISBN of this book is 0-908830-07-6
Good luck with whichever book(s) you find.
Regards,
Phil