Mnemonics for the places or pictures used by his predecessors. The historians of Mnemonics, especially Aretin, Reventlow, and the learned and famous bibliographer, Edward Marie Oettinger, in Leipzic, to whom I owe the above-mentioned and some of the following details on the history of Mnemonics, give a dozen other names of authors on Mnemonics belonging to this epoch.*

Edward Pick mentions Conrad Celtes in passing for having "made the great discovery that the alphabet could be substituted in Mnemonics for the places and pictures used by his predecessors. He doesn't provide a textual source for the information.

Pick indicates that his primary sources were Edward Marie Oettinger, (Johann Christoph Freiherr von) Aretin, and (Carl Otto) Reventlow who may have more detail on Celte's potential influence on the major system as well as potential alternate names from that era.

see also: - https://en.wikipedia.org/wiki/Eduard_Maria_Oettinger<br /> - History of Mnemonics by J. Ch, Baron von Aretin