Pipe organ (Simple English Wikipedia)

http://www.http Archived 2018-09-12 at the Wayback Machine://www.westminster-abbey.org/music/organ/organ-specification/ Archived 2008-05-12 at the Wayback Machine

ohscatalog.com (Global: low place; Simple English: low place)

"This site is under construction". www.ohscatalog.com. Archived from the original on 2008-02-25. Retrieved 2008-03-03.

"Friends of the Wanamaker Organ". Wanamakerorgan.com. 2010-07-22. Retrieved 2010-07-26.

http://www.http Archived 2018-09-12 at the Wayback Machine://www.westminster-abbey.org/music/organ/organ-specification/ Archived 2008-05-12 at the Wayback Machine
"American Theatre Organ Society". Atos.org. Archived from the original on 2010-12-12. Retrieved 2010-07-26.
"This site is under construction". www.ohscatalog.com. Archived from the original on 2008-02-25. Retrieved 2008-03-03.
"About the Ancient Hydraulis". The Archaeology Channel. 2002-03-14. Archived from the original on 2012-07-09. Retrieved 2010-07-26.