1. Dalton, J.: A New System of Chemical Philosophy. Cambridge University Pres, London (1808)
2. Loschmidt, J.: Chemische Studien I: Constitutiosformeln der Organischen Chemie in Graphischer Darstellung. Carl Gerold’s Sohn, Vienna (1861)
3. Bohr, N.: On the constitution of atoms and molecules, Part I. Phil. Mag. 26, 1–25 (1913)
4. Bohr, N.: On the constitution of atoms and molecules, Part II, systems containing only a single. Nucleus 26, 476–502 (1913)
5. Bohr, N.: On the constitution of atoms and molecules. Part III, Syst. Contain. Several Nuclei 26, 857–875 (1913)