"Introduction: New Perspectives on the 3rd Millenium" by Martin Furholt & "Was there ever a single Grave Culture in East Denmark? Traditions and Transformations in the 3rd Millennium BC" by Rune Iversen.
Both papers are about half-way down on the PDF.
An older paper I'm reading is "On the Outskirts of the European Bell Beaker Phenomenon - the Danish Case" by Torben Sarauw, 2007. Given that R1b is the second largest Dane lineage, maybe the outskirtishness and "borrowing of technologies" has been a bit oversold by Danish archaeology.