National geographic

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  Año 1977, Vol. 152, Número 4

  • Oases of life in the cold abyss

    John B. Corliss, Robert D. Ballard

    págs. 441-453

    

  • The Danube: river of many nations, many names

    Mike Edwards

    págs. 455-485

    

  • Arizona's suburbs of the sun

    David J. Jeffrey

    págs. 486-517

    

  • Where can the wolf survive?

    L. David Mech

    págs. 518-536

    

  • The Dominican Republic: caribbean comeback

    James Cerruti

    págs. 538-565

    

  • Geothermal energy: the power of letting off steam

    Kenneth F. Weaver

    págs. 566-579