α. 1900s– Dr. Martens, 1900s– Dr. Marten's, 1900s– Dr. Martins, 1900s– Dr. Martin's. Also without point.
β.   1900s– Doc Martens  Brit. /ˌdɒk ˈmɑːtᵻnz/, U.S. 
/ˌdɑk ˈmɑrtnz/,   1900s– Doc Marten's,   1900s– Doc Martins,   1900s– Doc Martin's. 
γ. 1900s– Doctor Martens, 1900s– Doctor Marten's, 1900s– Doctor Martins, 1900s– Doctor Martin's.
δ. As modifier or as singular form. 1900s– Doc Marten, 1900s– Doc Martin, 1900s– Doctor Marten, 1900s– Doctor Martin, 1900s– Dr. Marten, 1900s– Dr. Martin.