Hammann, K.; Wagner, H.-U. (2016): "Ein Stück Hamburg retten". Helmut Haeckel und der private Rundfunk ["Saving a Piece of Hamburg". Helmut Haeckel and Commercial Broadcasting]. In: Hamburger Flimmern, No. 23, November 2016, pp. 36-39 (pdf).
Hammann, K.; Wagner, H.-U. (2016): "Ein Stück Hamburg retten". Helmut Haeckel und der private Rundfunk ["Saving a Piece of Hamburg". Helmut Haeckel and Commercial Broadcasting]. In: Hamburger Flimmern, No. 23, November 2016, pp. 36-39 (pdf).
2016