In vols. for 1973-1983 odd numbered vols. cover Molecular aspects, even numbered vols. cover Cellular aspects. These vols. are published concurrently with one no. of each vol. issued each month, e.g., v. 131, no. 1 (Jan. 1973) covers Molecular aspects, and v. 132, no. 1 (Jan. 1973) covers Cellular aspects.