1. Bewege E, Gallion R (1967) Appl Spectr 21:20
2. Box GE, Wilson KB (1951) J Roy Statist Soc 13:1
3. Delijska A, Prav?eva Chr (1980) Rudodobiv 35:28
4. Jiglinski A, Kalmakov A, Tzarev V, Tscherbakov T (1978) Z Prikl Spektrosk 28:381
5. Jiglinski A, Kalmakov A (1978) VIII. Nat Conf on Atomic Spectr with Int Participation, Varna-Druzhba, Bulgaria, 25.?28. IX.