General/Algemeen
The Reed Organ Society, Inc. (ROS)
http://www.reedsoc.org  
The Classical Free-Reed, Inc.
http://trfn.clpgh.org/free-reed/
The Physics of the Pump Organ
http://www.bridgewater.edu/philo/philo96/knupp.html 
Harmonium in general
http://www.chembur.com/instruments/harmonium/harmonium.htm
Debain-Harmonium
http://www.orgelbits.de/debain.html
Choralcelo
http://members.shaw.ca/elnore/choralcelo.htm
http://jenkinsw0.tripod.com
Orgue-Harmonium.net
http://www.orgue-harmonium.net
Répertoire gratuit pour l'harmonium
http://repertoire-harmonium.blogspot.com
The Vocalion Group
http://www.sgeinc.com/~franktau/

Australia/Australië
Daniel Bittner's Reed Organ Collection
http://home.vicnet.net.au/~organs/

Belgium/België
Harmonium-art-museum "Huize Scelliana" Schelle, Belgium 
http://www.harmoniummuseum.centerall.com
Orgue Harmonium Net
http://orgue-harmonium.net
  

Canada
Kala Kendar
http://www.myharmonium.com
http://www.kalakendar.com

China
Harmonium
http://www.ywyueqi.com/eproductjt.asp

England/Engeland
Reed Organ and Harmonium Workshop
http://www.musiclink.co.uk/reedorgans/
American reed organ & Harmonium market place
http://www.reedorgans.co.uk/
Cambridge Reed Organs
http://www.harmonium.co.uk
Anne Page
http://www.anne-page.co.uk  
The Reed Organ in England
http://tardis.dl.ac.uk/FreeReed/organ_book/

Germany/Duitsland
GdO Arbeitskreis Harmonium
http://www.gdo.de/harmonium/
Harmonium Collection Averesch
http://www.harmoniumservice.de 
Rolf P. Leibold
http://www.rolf-leibold.de
Orgel- und Harmoniumwerkstatt Thomas Reilich
http://www.o-h-r.com
Jan Hennig
http://www.kunstharmonium.de 
Christian Meier, Orgel und Harmoniumbau
http://www.orgel-harmoniumbau.de
Beyer Klaviere
http://www.beyer-klaviere.de

India
Indian Harmoniums
http://chandrakantha.com/articles/indian_music/harmonium.html
Ali Akbar College Store (Indian harmoniums)
http://www.aacm.org/shop/harmonium.html
Indian Harmoniums (Delhi Musical Stores)
http://www.indianmusicalinstruments.com/harmoniums1.htm 
Dwarkin & Son (P) Ltd, Calcutta
http://www.dwarkin.com/
Keshav Music
http://www.keshav-music.com
BINA Musicals
http://www.binaswar.com  

Italy/Italië
Valdesi a pisa
http://www.comune.pisa.it/valdesiapisa/

Japan
Harmonium
http://www2.dokidoki.ne.jp/tayori04/reedorgan1/
Reed Organ Club Japan
http://www.reedorganclub.jp

Netherlands/Nederland
Harmonium Vereniging Nederland
http://www.harmoniumvereniging.nl  
Harmoniummuseum in Veenpark
http://www.harmonium-museum.nl 
Louis Huivenaar
http://www.harmoniums.com
Toetsinstrumenten
http://www.toetsinstrumenten.com
Harmoniumnet.nl
http://www.harmoniumnet.nl
Schüller Harmoniums
http://www.schueller-harmoniums.nl
Wim Rhebergen
http://www.rhegie.com

Noorwegen/Norway
Harmonium-entusiaster i Norge
http://www.harmonium-orgel.com
Harmonium i Norge
http://sites.google.com/site/harmoniumorgel/

Spain/Spanje
Taller de Restauración del Armonio
http://www.armonio.net

Switserland/Zwitserland
Harmoniummuseum Liestal Dieter Stalder
http://www.harmoniummuseum.ch
Mark Richli
http://www.harmonium.ch