I. P. Gragerov, M. P. Ponomarchuk, V. V. Strelko, L. N. Ganyuk, Z. Z. Vysotsky, “Radicalization of benzoquinhydrone and phenazohydrin on solid surfaces as investigated by means of electron spin resonance”, Dokl. Akad. Nauk SSSR, 147:4 (1962), 867–869
