1. (a) T. Umemoto and K. Tomita, (1986), N-FLUOROPYRIDINIUM TRIFLATE AND ITS ANALOGS, THE FIRST STABLE 1:1 SALTS OF PYRIDINE NUCLEUS AND HALOGEN ATOM
2. Tetrahedron Lett. 27, 3271-3274. (b) T. Umemoto, K. Kawada, and K. Tomita, (1986), N-FLUOROPYRIDONIUM TRIFLATE AND ITS DERIVATIVES: USEFUL FLUORINATING AGENTS
3. Tetrahedron Lett. 27, 4465-4468. (c) T. Umemoto, S. Fukami, G. Tomizawa, K. Harasawa, K. Kawada, and K. Tomita, (1990), Power- and structure-variable fluorinating agents. The N-fluoropyridinium salt system
4. (a) T. Umemoto and K. Tomita, (1986), N-FLUOROPYRIDINIUM TRIFLATE AND ITS ANALOGS, THE FIRST STABLE 1:1 SALTS OF PYRIDINE NUCLEUS AND HALOGEN ATOM; Tetrahedron Lett. 27, 3271-3274.
5. (b) T. Umemoto, K. Kawada, and K. Tomita, (1986), N-FLUOROPYRIDONIUM TRIFLATE AND ITS DERIVATIVES: USEFUL FLUORINATING AGENTS; Tetrahedron Lett. 27, 4465-4468.