1. Uchikawa : Bunseki, Ho. 3 (1981) 163-169
2. Goshi et al. : Adv. X. Ray Anal., vol. 28 (1985) 61-68, Jpn. J. Appl Phys., vol. 23, No. 11 (1984) 1543-1544, and Anal. Chem. vol. 58 (1986) 394-397
3. Arai and Ryon : Adv. X-Ray Anal., vol. 28 (1985) 137-144