Grey-headed woodpecker Southern Europe. There is contradictory information regarding its occurrence in Turkey. Most likely, several hundred pairs breed in Mittelgebirge habitats of the Pontic Mountains. The species is absent from the North German Plain, British Isles, Iberian Peninsula, and Mediterranean islands. In Italy, it is confined to the northernmost parts. The grey-headed woodpecker is a somewhat less specialised ant hunter than the European green woodpecker. In its foraging strategy it is intermediate between many "Dendrocopos" species on the one hand, and the often ant-specific members of the genus "Picus". This reduced ant specialisation of the grey-headed woodpecker allows it to be
An Essay on the Nature and Significance of Economic Science on economic methodology in generating a range of tightly-argued, radical implications from a simple definition, for example in admitting an "aspect" of behaviour (rather than a list of behaviours) but not limiting the subject-matter of economics, provided that the influence of scarcity impinges on these (pp. 16–17). The broad behavioural definition is credited for its consistency with the expanding boundaries of economics decades later. In this Robbins both narrows the definition of economics, thereby demonstrating the usefulness of deduction, and opens up the subject-matter of economics. Robbins's "Essay" is one of the most-cited works on the methodology and philosophy of