Otterbech, Finn (Fiskeridirektoratets skrifter, Serie Havundersøkelser, Research report, 1954)
"The Cod Population of the Oslofjord".
The hydrographical conditions of the fjord are mentioned. Owing
to the sills at Drøbak and Nesodden the water masses of the inner
fjord are often insufficiently aerated (Fig. 1 ...