Martin Hellwig, "Rational Expectations and the Markov Property of Temporary Equilibrium Processes," Journal of Mathematical Economics 9, 135-144 (1982).

Martin Hellwig, "Rational Expectations Equilibrium with Conditioning on Past Prices: A Mean-Variance Example," Journal of Economic Theory 26, 279-312 (1982).

Martin Hellwig, "Zur Informationseffizienz des Kapitalmarktes," Zeitschrift für Wirtschafts- und Sozialwissenschaften 102, 1-27 (1982).