He has co-authored (with Eamonn Butler) "Test Your IQ", "Boost Your IQ", and "The Sherlock Holmes IQ Book".
Butler | Eamonn Andrews | Gerard Butler | Judith Butler | West Chester Township, Butler County, Ohio | Samuel Butler | Butler Derrick | Butler County | James Butler, 1st Duke of Ormonde | John Butler Trio | Jonathan Butler | Butler County, Kentucky | Samuel Butler (novelist) | John Butler Yeats | Butler County, Ohio | Robert Olen Butler | Rhett Butler | Pierce Butler | James Butler, 2nd Duke of Ormonde | Butler, Waukesha County, Wisconsin | Butler County, Pennsylvania | Richard Butler | Ellis Parker Butler | Eamonn Walker | David Butler | Cropwell Butler | Cranberry Township, Butler County, Pennsylvania | Butler Institute of American Art | butler | Vicki Butler-Henderson |
Sherlock Holmes IQ Book: Test Your I.Q. Against the Great Detective (with Eamonn Butler, 1995)