 | This article was nominated for deletion on 6 April 2009 (UTC). The result of the discussion was no consensus. |
Copied from the PROD reason, when I deprodded, to facilitate further discussion: DGG (talk) 20:26, 6 April 2009 (UTC)
concern = These terms are inherently loosely and inconsistently defined by authors who use them, and there is no source that establishes them as a concrete and cohesive series as purported by this article. The sources given do not meet WP:RS as reliable sources, and in any event references can't be used to back up these definitions because, as I said, different references use different definitions, or else they concede that the boundaries are vague.