1. Akila L., Roopkumar R.: A natural convolution of quaternion valued functions and its applications. Appl. Math. Comput. 242, 633–642 (2014)
2. Akila, L., Roopkumar, R.: Ridgelet transform on quaternion valued functions. (submitted)
3. Bhuvaneswari R., Karunakaran V.: Boehmians of type S and their Fourier transforms. Ann. Univ. Mariae Curie–Skłodowska Sect. A 64, 27–43 (2010)
4. Fu Y.X.: Non-harmonic quaternion Fourier transform and uncertainty principle. Integral Transform. Spec. Funct. 25, 998–1008 (2014)
5. Gröchenig, K.: Foundations of Time–Frequency Analysis. Birkhäuser, Basel (2001)