• Matrix transforms into the speed-Maddox spaces over ultrametric fieldsNatarajan, Pinnangudi Narayanasubramanian; Aasma, AntsAnalele Stiintifice ale Universitatii Al I Cuza din Iasi - Matematica2025 / p. 71-79 https://doi.org/10.47743/anstim.2025.00006 https://www.math.uaic.ro/~annalsmath/pdf-uri_anale/F1(2025)/6%20F1%202025.pdf
• Matrix Transforms Into the Speed-Maddox Spaces Over Ultrametric Fields IINatarajan, Pinnangudi Narayanasubramanian; Aasma, AntsPublications de l Institut Mathematique2025 / p. 89-96 https://doi.org/10.2298/PIM2532089N http://elib.mi.sanu.ac.rs/files/journals/publ/138/publn138p89-96.pdf