| 1-enkelt.dk |
| Angostura Ltd. |
| anthon-thorup.dk |
| The Bitter Truth - Cocktail bitters |
| Bittermens Bitters |
| Bitters - Wikipedia, the free encyclopedia |
| Bitters & Twisted | bringing drinks to life |
| Bokers Bitters.co.uk |
| Dr. Adam Elmegirab's Article 1 - A Bitter Sweet Symphony |
| DrinkBoy The Lost Art of Bitters |
| En Kelt Bitters (in Danish) |
| Fee Brothers - Rochester, NY |
| Fernet Branca – Digestivo amaro - Distillerie Fratelli Branca |
| Gammel Dansk (link to site in English) |
| HAVE, the Averna Bitter USA website... Have a drink, have a good time, have a chance |
| Mixellany Limited |
| Montenegro Srl |
| Peychaud's Bitters by the Sazerac Company |
| The Lost Art of Bitters - an article on Drinkboy |
| The Sazerac Company, New Orleans, LA - Peychaud's Bitters |
| Scrappy' s Bitters |
| Small Hand Foods | Classic ingredients for pre-prohibition era cocktails |
| The stork - Genevas and Liquors - A. of orphan Amsterdam |
| Underberg - der natürliche Kräuter-Digestif (link to site in English) |
| Urban Moonshine - Handcrafted Organic Bitters, Tonics & Tinctures made in Vermont |
| Vinfirma A/S ANTHON THORUP & SØN (in Danish) |
| Von Oosten Bitter (in Danish) |
