"Series Foreword", in: Georg Goldrian, eds., Handbook of Survey-Based Business Cycle Analysis, Ifo Economic Policy Series, Edward Elgar Publishing: Cheltenham, 2007; (Download, 1.4 MB).

"Foreword", in: Jan-Egbert Sturm andTimo Wollmershäuser, eds., Ifo Survey Data in Business Cycle and Monetary Policy Analysis, Springer Book Series „Contributions to Economics“, Physica-Verlag Heidelberg, 2005, pp. V-VI; (Download, 78 KB).

"Foreword", CESifo Economic Studies 49, No. 1, 2003, p. 1; (Download, 105 KB).