[en] The data of the fourth column of table 3 (S(X) IAM), reported on pages 2556 and 2557, were erroneously scaled by a factor √M, with M the molecular mass of the compound. Therefore, the data of S(X) IAM for PMMA on page 2556 and the data of S(X) IAM for fat on page 2557 must be multiplied by a factor of 10.01 and 29.21 respectively. Moreover, due to a mistake in Thompson expression evaluations, the data of Bradley et al (1989) reported in figure 1 had results enhanced beyond x=2.5 mm^-1. After the proper computation, these discrepancies were removed. The results of molecular differential cross section and form factor for coherent scattering presented in the original version remain correct. The authors' thanks are due to Dr Robert Leclair - from Carleton, Canada - and to Dr David Dance - from London, UK - for pointing out these errors which were due to the same computer program mistake in forming the final tabulations and graphic files. (author)