<html><head><meta http-equiv="content-type" content="text/html; charset=utf-8"></head><body dir="auto"><span style="background-color: rgba(255, 255, 255, 0);">Dear Colleagues,</span><div><span style="background-color: rgba(255, 255, 255, 0);">For your general interest, you can find the lecture slides that I presented at ACA 2019 in the Transactions Symposium on Data via the weblink here:-</span></div><div><font color="#000000"><span style="caret-color: rgb(0, 0, 0); background-color: rgba(255, 255, 255, 0);"><a href="https://forums.iucr.org/viewtopic.php?f=39&amp;t=421">https://forums.iucr.org/viewtopic.php?f=39&amp;t=421</a>&nbsp;</span></font></div><div><span style="background-color: rgba(255, 255, 255, 0);">Best wishes,</span></div><div><span style="background-color: rgba(255, 255, 255, 0);">John&nbsp;<br></span><div dir="ltr"><span style="background-color: rgba(255, 255, 255, 0);">Emeritus Professor John R Helliwell DSc</span><div><span style="background-color: rgba(255, 255, 255, 0);">Chairman of IUCr CommDat&nbsp;</span></div></div></div></body></html>