ACE:10.4319/lo.1970.15.2.0257
ACE:10.4319/lo.1971.16.6.1006
ACE:10.4319/lo.1974.19.2.0297
ACE:10.4319/lo.1987.32.1.0112
ACE:10.4319/lo.1988.33.4part2.0848
ACE:10.4319/lo.1992.37.2.0315
ACE:10.4319/lo.1992.37.8.1705
ACE:10.4319/lo.1993.38.6.1200