Smith, Charles Allen (1972) Closed circular DNA in animal cells: I. Complex mitochondrial DNA in normal and malignant tissue and the in vivo effects of drugs on the superhelix density of mitochondrial DNA. II. Small polydisperse circular DNA of HeLa cells. III. Sequence heterogeneity in closed simian virus 40 deoxyribonucleic acid (Dissertation (Ph.D)), California Institute of Technology doi: 10.7907/RHBK-9856