||Duursma EK, Boisson MPRM, Global oceanic and atmospheric oxygen stability considered in relation to the carbon-cycle and to different time scales. Oceanologica Acta (0399-1784) (Gauthier-Villars), 1994 , Vol. 17 , N. 2 , P. 117-141 link p.129 left column bottom paragraph
||Holland D. (1978). The Chemistry of the Atmosphere and Oceans. John Wiley and Sons, New York, USA, 351 pp.
||P.129 left column bottom paragraph: "Just as in the case of natural waters, [investigators] can speak of a chemical oxygen demand (COD) which is herewith defined as the annual oxygen consumption by reductive atmospheric compounds. Holland (primary source) gives a COD value of 3.1 x 10^12 mol O2/yr for the volcanic gases consuming oxygen."