National geographic

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  Año 1977, Vol. 152, Número 2

  • West Germany: continuing miracle

    John J. Putman

    págs. 149-181

    

  • On the trail of Wisconsin's Ice Age

    Anne Labastille

    págs. 182-205

    

  • The air-safety challenge

    Michael E. Long

    págs. 209-234

    

  • Penguins and their neighbors

    Roger Tory Peterson

    págs. 237-254

    

  • Five times to Yakutsk

    Dean Conger

    págs. 256-269

    

  • Purdah in India: life behind the veil

    Doranne Wilson Jacobson

    págs. 270-286

    

  • How soon will we measure in metric?

    Kenneth F. Weaver

    págs. 287-294