The Library of Congress is unaware of any copyright or other restrictions in the World Digital Library Collection. Absent any such restrictions, these materials are free to use and reuse. Researchers are encouraged to review the source information attached to each item. For information on contacting WDL partner organizations, see this archived list of partners

The Library asks that researchers approach the materials in this collection with respect for the culture and sensibilities of the people whose lives, ideas, and creativity are documented here.

Credit Line: [Original Source citation], World Digital Library

More about Copyright and other Restrictions

For additional information and contact information for many of the partner organizations, see this archived capture of the World Digital Library site from 2021.

For guidance about compiling full citations consult Citing Primary Sources.

Manuscript/Mixed Material Image 23 of Kashf al-qināʻ fī waḍʻ al-arbāʻ min al-jihat al-sitt fī ʻilm al-falak