Clark Wissler 
Sun Dance of the Blackfoot Indians [PDF ebook] 

Whilst the greatest effort has been made to ensure the quality of this text, due to the historical nature of this content, in some rare cases there may be minor issues with legibility. The publication of this study of the sun dance has been long delayed in the hope that circumstances would permit a more intensive study of the ceremony among the Canadian divisions. But the time for making such a study has really passed, since those natives who had the knowledge essential to an accurate exposition of the sun dance are now dead. It seems advisable, therefore, to publish the data as they stand.