International
Tables for Crystallography Volume H Powder diffraction Edited by C. J. Gilmore, J. A. Kaduk and H. Schenk 
International Tables for Crystallography (2018). Vol. H, ch. 3.1, p. 239
Figure 3.1.26^{a}National Institute of Standards and Technology, Gaithersburg, Maryland, USA 

Figure 3.1.26
Δ(2θ) curve using SRM 660b illustrating the peakposition shifts as function of 2θ. The peak positions were determined via a secondderivative algorithm, and Δ(2θ) values (SRM − test) were fitted with a thirdorder polynomial. Simulated data are from FPAPC and were analysed via the secondderivative algorithm and polynomial fits as per the experimental data. 