TY - JOUR T1 - Another way of looking at the species problem: a reply to de Queiroz and Donaghue JF - Cladistics Y1 - 1990 A1 - Wheeler, Q. D. A1 - Nixon, Kevin C. SP - 77 EP - 81 KW - CLADISTICS KW - species KW - SPECIES CONCEPTS VL - 6 ER - TY - JOUR T1 - On Outgroups JF - Cladistics Y1 - 1993 A1 - Nixon, Kevin C. A1 - Carpenter, J. C. SP - 413 EP - 426 KW - CLADISTICS KW - OUTGROUPS VL - 9 ER - TY - JOUR T1 - On concensus, collapsibility, and clade concordance JF - Cladistics Y1 - 1996 A1 - Nixon, Kevin C. A1 - Carpenter, James M. SP - 305 EP - 321 KW - Clade KW - CLADISTICS VL - 12 ER - TY - JOUR T1 - An amplification of the phylogenetic species concept JF - Cladistics Y1 - 1990 A1 - Nixon, Kevin C. A1 - Wheeler, Q. D. SP - 211 EP - 223 KW - CLADISTICS KW - PHYLOGENETIC SPECIES CONCEPT KW - species VL - 6 N1 - An excellent and concise account of the PSC; ; ;, ER - TY - JOUR T1 - Populations, genetic variation, and the delimitation of phylogenetic species JF - Systematic Biology Y1 - 1992 A1 - Davis, Jerrold I. A1 - Nixon, Kevin C. SP - 421 EP - 435 KW - PHYLOGENETIC SPECIES CONCEPT KW - species VL - 41 ER -