You'd have thought that they'd have researched the time frame properly, not that it matters to most punters.
Quote from Wikipedia:
It was in their shop that Godin coined the term 'northern soul',[4] a description that he would popularise through his work as a music journalist. In a 2002 interview with Chris Hunt of Mojo, he explained that he had first come up with the term in 1968 as a sales reference to help staff in his shop differentiate the more modern funkier sounds from the smoother, Motown-influenced soul of a few years earlie:
:"I had started to notice that northern football fans who were in London to follow their team were coming into the store to buy records, but they weren't interested in the latest developments in the black American chart. I devised the name as a shorthand sales term. It was just to say "Ëœif you've got customers from the north, don't waste time playing them records currently in the US black chart, just play them what they like - "ËœNorthern Soul'.