"Between 1876 and 1928, twenty-seven different publishers issued titles under the name Bertha M. Clay. Six novels were translated into other languages. Bertha M. Clays appeared in fourteen different series and eleven different 'libraries'." Books could appear under different titles, some staying in print for 47 years.[2]
Street and Smith's "new Bertha M. clay Library" ran to more than four hundred volumes.[2]