Recent developments on absolute geometries and algebraization by K-loops. - Helmut Karzel (Discret. Math., 1999)

⁶⁷Zn-Mössbauereffektmessungen an ZnO und ZnSe unter hohen externen Drücken und an nanokristallinem ZnO bei Normaldruck - Helmut Karzel (1999)

Co-Minkowski spaces, their reflection structure and K-loops. - Luca Giuzzi; Helmut Karzel (Discret. Math., 2002)

K-loops derived from Frobenius groups. - Helmut Karzel; Silvia Pianta; Elena Zizioli (Discret. Math., 2002)

Introduction of measures for segments and angles in a general absolute plane. - Helmut Karzel; Mario Marchi (Discret. Math., 2008)

Binary operations derived from symmetric permutation sets and applications to absolute geometry. - Helmut Karzel; Silvia Pianta (Discret. Math., 2008)