12Moore, Sam. "Myths and Folklore as Aids in Interpreting the Prehistoric Landscape at the Carrowkeel Passage Tomb Complex, Co. Sligo, Ireland." Folk Beliefs and Practice in Medieval Lives. Ed. Ann-Britt Falk and Donata M. Kyritz. Oxford: Archaeopress, 2008. 23-4. This article may be read in its entirety here.
According to the author, evidence of secondary cist burials were found in cairn B. Macalister found in Cairn O "heaped up discs of sandstone, burnt and unburnt bone and ashes with a secondary vase food vessel placed above these."