فلف
Heinrich founded, owns and manages the publishing company MatrixMedia Verlag in Göttingen. The focal point of the house is history, namely local history of the state of Lower Saxony, of which the predecessor states were the Kingdom of Hanover and the Duchy of Brunswick, furthermore the history of the House of Welf, but also general historical items. The company publishes books, monographs, historiographies, memoirs, illustrated books and films. Furthermore, he is responsible for a website on the House of Welf called "Welfen.de"