Hi, Lyn. Cutter rarely gives his sources and so he must be used with caution. Some of his work is correct and other of it is not. Unless he is giving his sources, what he states should be supported by primary source documentation. In the case of Walter Filer who was has been researched by Robert Anderson, if there are conflicts between Anderson and Cutter, Anderson would be considered the authority. If there is not conflicting information between Cutter and Anderson, I think you could add the Cutter citation in a "See Also" category under Sources.