von der Lippe, Peter (2012): Covariances and relationships between price indices: Notes on a theorem of Ladislaus von Bortkiewicz on linear index functions. Unpublished.
von der Lippe, Peter (2008): Index Formula of Laspeyres and the Inversion Test. Unpublished.
von der Lippe, Peter (2007): Price indices and unit value indices in German foreign trade statistics. Unpublished.
von der Lippe, Peter (2010): The Interpretation of Unit Value Indices - Unit Value Indices as Proxies for Price Indices. Unpublished.
