1. “The Machinery of the Body.”;Carlson,1956
2. Optimal systems: I. The vascular system;Cohn;Bull. Math. Biophys.,1954
3. Optimal systems: II. The vascular system;Cohn;Bull. Math. Biophys.,1955
4. “Textbook of Anatomy”;Cunningham,1919
5. Tree trunks and branches as optimum mechanical supports of the crown: I. The trunk;Esser;Bull. Math. Biophys.,1946