https://digital.library.lse.ac.uk/Documents/Detail/report-on-the-census-of-production-for-1992.-pa246-abrasive-products/459919
Report on the Census of Production for 1992. PA246 Abrasive products - LSE Digital Library
https://digital.library.lse.ac.uk/Documents/Detail/report-on-the-census-of-production-for-1983.-pa246-abrasive-products/448570
Report on the Census of Production for 1983. PA246 Abrasive products - LSE Digital Library
https://digital.library.lse.ac.uk/Documents/Detail/report-on-the-census-of-production-for-1988.-pa246-abrasive-products/456240
Report on the Census of Production for 1988. PA246 Abrasive products - LSE Digital Library