275707
He specialized in the design of libraries , such as the Olean Public Library and Mount Pleasant Library ( Washington , D.C. ) , two of about a hundred libraries , many of them Carnegie libraries , that he designed in the United States and Canada , and structures for educational institutions .
 None
Please list all entity words in the text that fit the category. Output format is "word1, word2". 
Option: location, person, organization 
Text: {0} 
Answer:
 None