よくある質問 - CiNii Dissertationsで検索した博士論文を利用するには

If there is no “Access this paper” icon, this means no link to the full text is available in CiNii Dissertations.
Try to obtain the full text by the following means
(We do not offer photocopying or procurement services for dissertations.)

• Use the National Diet Library
  

  The Kansai-kan of the National Diet Library archives doctoral dissertations. Since that facility offers photocopying services, try contracting the NDL directly.
  Note that the "NDLONLINE" button under "Search this paper" links to the National Diet Library NDLONLINE. Persons registered with the NDL can request photocopies directly.

• If "NDL Digital Collection (NDL premises only)" is displayed
  

  The paper can be accessed only from terminals on the premises of the National Diet Library.

• If "NDL Digital Collection (Distributed only to libraries)" is displayed
  
  1. Persons affiliated with a university or other such institution
     Inquire with the library or media center, etc. of your institution.
  2. Persons not affiliated with a university or other such institution
     Check with a local public library, which may have terminals from which the paper can be accessed.

See also the following
Japanese Doctoral Dissertations | How to Find | National Diet Library