| Bulletin of the National Museum of Nature and Science Series E (Physical Sciences & Engineering) | date of publication | 
    
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      | Bulletin of the National Museum of Nature and Science Series E (Physical Sciences & Engineering) Volume 44 | December 2021 | 
    
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      |  | Fuuka Hishiki: | P.1 | 
    
      |  | Reexamination of Notebooks Contained in Hantaro Nagaoka Papers in
Professor Period and RIKEN Period |  | 
    
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      |  | Takahiko Kutsuna and Tomoya Yoshida: | P.17 | 
    
      |  | Non-destructive Analysis of Artifacts Utilized for Non-ferrous Metalworking from Iwabitsu Castle Ruins in Gunma Prefecture |  | 
    
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      |  | Masahiro Maejima: | P.29 | 
    
      |  | Retyping and Introducing of Letters Written by W. E. Ayrton 【NOTE】 |  | 
    
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