https://digital.library.lse.ac.uk/Documents/Detail/report-on-the-census-of-production-for-1973.-pa394-wire-and-wire-manufactures/433222
Report on the Census of Production for 1973. PA394 Wire and wire manufactures - LSE Digital Library
https://digital.library.lse.ac.uk/Documents/Detail/report-on-the-census-of-production-for-1979.-pa394-wire-and-wire-manufactures/443193
Report on the Census of Production for 1979. PA394 Wire and wire manufactures - LSE Digital Library