Ryan, D. L., & Young, D. (1992). Searching for valid instruments: Removing barriers to instrument selection. Univ. of Alberta, Department of Economics.
Chicago-Zitierstil (17. Ausg.)Ryan, David L., und Denise Young. Searching for Valid Instruments: Removing Barriers to Instrument Selection. Edmonton, Alberta: Univ. of Alberta, Department of Economics, 1992.
MLA-Zitierstil (9. Ausg.)Ryan, David L., und Denise Young. Searching for Valid Instruments: Removing Barriers to Instrument Selection. Univ. of Alberta, Department of Economics, 1992.
Achtung: Diese Zitate sind unter Umständen nicht zu 100% korrekt.