Publishers
- Ant Belmont 1
- Anthony Blond 1
- Anthony Nelson Ltd. 3
- Anthony Treherne & Co. Ltd. 2
- Antique Collectors' Club 10
- Antonio Delfino Editore 1
- Antony Atha 1
- Anuart Ediciones 1
- Apach Publishing 1
- Apecs Press 2
- Apple Press 1
- Apple Tree Press 1
- Appletree Press 1
- Applied Science Publishers Ltd. 4
- Aquarian Thorsons 1
- Arandar Books Ltd. 2
- Arbeit Munich 1
- Arcadia 4
- Archaeologia Cambrensis 1
- Archangel Press 2
- Archibald Constable & Co. Ltd. 5
- Archibald Constable & Company 1
- Archibald Constable And Co. 1
- Archibald Constable And Company 1
- Architectural And Archaeological Society Of Durham And Northumberland 1
- Architectural Press 1
- Archon Books 3
- Arco 1
- Arco Publications 2
- Arco Publishing 3
- Arcos Verlag 1
- Arctic Fox Books 1
- Arcturus Publishing Ltd. 1
- Argraffdy'R Methodistiaid Calfinaidd 1
- Argus Books 6
- Argyll Publishing 2
- Arkstee & Merkus 1
- Arlequin Press 1
- Arlington Books 2
- Armada 9
- Arman Enterprises, Inc. 1
- Arms & Armour Press 27
- Army Apprentices College Chepstow 1
- Arner Publications 1
- Arno Press 1
- Arnold 2
- Arrow Publishing 1
- Arrowsmith 2
- Art & Educational Publishers Limited 2
- Art & Humour Publishing Co. 3
- Art & Humour Publishing Co. Ltd. 1
- Art And Educational Publishers Ltd. 1
- Art Books International 1
- Art Gallery Of Alberta 1
- Art Gallery Of Western Australia 1
- Art Services International 1
- Artabras 1
- Artech House 1
- Arthur A. Levine 1
- Arthur Ackermann 1
- Arthur Barker Limited 10
- Arthur Barker Ltd. 8
- Arthur Barron Ltd. 3
- Arthur Gray-Jones 1
- Arthur H. Stockwell 1
- Arthur H. Stockwell Ltd. 6
- Arthur L. Humphreys 1
- Arthur Wigley & Sons Ltd. 1
- Arti Grafiche Gajani 1
- Artia 1
- Artis-Historia Publishing 1
- Artist's Valley Press 1
- Artists & Writers Guild 1
- Arts and General Publishers Ltd. 1
- Artur Wolf 1
- Arundel Prints 1
- Ascherberg, Hopwood & Crew Ltd. 4
- Ashford 1
- Ashford Press Publishing 1
- Ashgate 4
- Ashgate Publishing Company 2
- Ashgrove Press 1
- Asia Publishing House 2
- Aslib 2
- Associated Newspapers 3
- Associated Newspapers Ltd. 6
- Associated University Press 1
- Association Of The United States Army 1
- Aston Martin 1
- Aston Publications 15
- Atelier Books 2
- Atheneum 3
- Atlantic Book Publishing Co. Ltd. 3
- Atlantic Books 4
- Atlantic Monthly Press 3
- Atlantic Publishers 5
- Atlantic Transport Publishers 1
- Atlas Books 1
- Atlas Publishing Co. Ltd. 1
- Atrium Press Ltd. 1