B. MOSTAFA, S. M. HABIBI-KHORASSANI, and M. SHAHRAKI, “KINETIC ASPECTS OF 3, 4 dihydropyrano[c]chromenes FORMATION IN THE PRESENCE OF DIFFERENT CATALYSTS: A MECHANISTIC INVESTIGATION”, JACSI, vol. 5, no. 3, pp. 121-133, Nov. 2015.