I have the book by Dorothy Morland Hooper and I think it's a good book, originally written pre-war and then updated but it was generally before the show/working split and a lot of the information is seen as 'old fashioned' now. I think both Don Miller & Colin Muirhead have written good books covering the breed - Colin Muirhead's may contain a bit more about working (I'm not sure though) as his Shipden's are dual purpose.
i have a collins one called english springer spaniel by yvonne billows. i found it very interesting and helpful to read. and was just bought from pets at home.