1. Becker, M., Umkehrsätze für positive lineare Operatoren, Dissertation, RWTH Aachen 1977.
2. Becker, M., An elementary proof of the inverse theorem for Bernstein polynomials . Aequationes Math, (in print).
3. Becker, M., Global approximation theorems for Szász-Mirakjan and Baskakov operators in polynomial weight spaces. Indiana Univ. Math. J. (in print).
4. Becker, M., Inverse theorems for Favard operators in weighted spaces.(to appear).
5. Becker, M..- Butzer, P.L. - Nessel, R.J., Saturation for Favard operators in weighted function spaces. Studia Math. 59 (1976), 33–47.