1. The American species of Crepis.;Babcock;Carn. Inst. Wash. Publ.,1938
2. Control of flowering with cytohormones.;Clark;Science, Vol.,1942
3. Experimental studies on the nature of species. II. Plant evolution through amphiploidy and autoploidy with examples from the Madiinae.;Clausen;Carn. Inst. Wash. Publ.,1945
4. Experimental taxonomy.;Clausen;Carn. Inst. Wash. Year Book,1947
5. Experimental taxonomy;Clausen;Carn. Inst. Wash. Year Book,1948