Haruyasu Asahara, Mai Hamada, Nagatoshi Nishiwaki, ‘‘Hantzsch-type Reaction of β-Formyl-β-nitroenamine: Multi-component Synthesis of 4-Substituted-3,5-dinitro-1,4-dihydropyridine’’, 25th International Society of Heterocyclic Chemistry Congress (ISHC-2015), 0014, UC Santa Barbara, USA, Aug 2015 (oral presentation)