Phi-functions for primary 2D-objects. - Yurij Stoyan; Johannes Terno; Guntram Scheithauer; Nikolay Gil; Tatiana E. Romanova (Stud. Inform. Univ., 2002)

Phi-functions for complex 2D-objects. - Yurij Stoyan; Guntram Scheithauer; Nikolay Gil; Tatiana E. Romanova (4OR, 2004)