Symposium on the Biology of the seal 14 - 17 August 1972
1972
International Biological Programme (IBP)
Productivity and conservation in northern circumpolar lands : proceedings of a conference, Edmonton, Alberta, 15-17 October 1969
1970
Fuller, W. A. |
Kevan, P. G. |
Project aqua : a source book of inland waters proposed for conservation
1971
Luther, H. |
Rzóska, J. |
Worthington, E. B. |