https://digital.library.lse.ac.uk/Documents/Detail/report-on-the-census-of-production-for-1972.-pa418-lace/431439
Report on the Census of Production for 1972. PA418 Lace - LSE Digital Library
https://digital.library.lse.ac.uk/Documents/Detail/report-on-the-census-of-production-for-1976.-pa418-lace/437617
Report on the Census of Production for 1976. PA418 Lace - LSE Digital Library