I tried googling "images" for starters, with several variations in search terms. One potentially relevant page that came up eventually {linked to the "image" google retrieved} is http://www.northvegr.org/lore/swastika/020.php - and between "fig. 41" on the page and the text {beginning w/the 2nd paragraph, "Cartailhac says: (1)" } - this seemed at least looking at.

... In Europe it appeared about the middle of the civilization of the bronze age, and we find it, pure or transformed into a cross, on a mass of objects in metal or pottery during the first age or iron. Sometimes its lines were rounded and given a graceful curve instead of straight and square at this ends and angles. [See letter by Gandhi, pp. 803, 805.] ... [2] the association (in fig. 41) on a slab from the lake dwellings, of the Maltese cross and reproduction of the triskelion; [3] a tetraskelion, which he calls a Swastika "flamboyant," being the triskelion, but with four arms ...
I tried reading more fully, but my eyes began glazing over

Maybe that info will lead to something more, search-wise?