Lattice generation program for computing a vector space lattice LENNI HAAPASALO; PEKKA NIEMISTÖ — 1983 Beiträge zur Algebra und Geometrie = Contributions to algebra and geometry
Educational technology standards in professional development of mathematics teachers: an international study Đorđe Kadijević; Lenni Haapasalo; Jozef Hvorecky — 2005 The Teaching of Mathematics
A Versatile Tool to Promote Link Between Creative Production and Conceptual Understanding Lenni Haapasalo; Bernd Zimmermann; Hartmut Rehlich — 2004 The Teaching of Mathematics
Using Innovative Technology for Revitalizing Formal and Informal Mathematics: a Special View on the Interplay Between Procedural and Conceptual Knoledge Lenni Haapasalo; Đorđe Kadijević — 2003 The Teaching of Mathematics
Looking at Function Concept Through Interactive Animations Martti E. Pesonen; Lenni Haapasalo; Hanna Lehtola — 2002 The Teaching of Mathematics
Critical look at dynamic sketches when learning mathematics Martti E. Pesonen; Lenni Haapasalo; Timo Ehmke — 2006 The Teaching of Mathematics