1. “A micromethod for the determination of xanthine and guanine in urine.”;Williams;Ibid.,1950
2. “The identification of 6-succinoaminopurine and of 8-hydroxy-7-methyl-guanine as normal human urinary constituents.”;Weissman;Ibid.,1957
3. “Differential spectrophotometry of purine compounds by means of specific enzymes.”;Kalckar;Ibid.,1947
4. “A study of the metabolism of theobromine, theophylline and caffeine in man.”;Cornish;J. biol. Chem.,1957