Okay, the Robert Holden / Mary Worrall marriage is listed on Lancashire BMD as 1928, Salford Christ Church, and on the GRO index as Jul-Sep 1928.
You can order a copy of the marriage certificate either from Lancashire:
http://www.lancashirebmd.org.uk/index.php
or from the GRO:
https://www.gro.gov.uk/gro/content/c...es/default.asp
If you order from the GRO, the GRO Reference is Jul-Sep 1928, district Salford, volume 8d, page 886.
You say that Robert died in 1978. Do you know where he died, please? I can't see a likely death on the GRO index, or did he die in another country?