Brackx:1992:CAL Brackx:1992:CAL Davenport:1988:CAS Davenport:1988:CAS Davenport:1993:CAS Davenport:1993:CAS Flatau:reduce Flatau:1988:SAA Hearn:reduce Hearn:1993:RUM Hehl:1992:CKA Hehl:1992:CAK Hirota:1989:IRD Hirota:1989:IRD MacCallum:1991:ACR MacCallum:1991:ACR Marti:1993:REA Marti:1993:REA Nakamure:reduce Nakamura:1989:SCS Ochiai:reduce Ochiai:1990:LAU Rayna:1987:RSA Rayna:1987:RSA Stauffer:1993:CSC Stauffer:1993:CSC Steeb:1992:ACR Steeb:1992:ACR Steeb:1992:CFA Steeb:1992:CFA Steeb:1994:QMU Steeb:1994:QMU Ueberberg:1992:ECR Ueberberg:1992:ECR Winkelmann:reduce Winkelmann:1988:RBS Winkelmann:1993:CSC Winkelmann:1993:RBS