| abortion clinics | abrasive products | accommodation |
| accountant | accounting | accounting general services |
| accounting services | acting school | acupuncture clinic |
| adhesive manufacturer | adjustment services | adm-communications |
| adm-communications utilities | administration of educational programs | administration of general economic programs |
| administration of manpower programs | administration of public health programs | administration of social programs |
| administration of transportation | administration of veterans' affairs | adoption attorneys |
| advertising | advertising-computer | advertising-outdoor |
| advertising-promotional | advertising agencies | advertising counselors |
| advertising specialties | after school care | after school programs |
| air cargo services | air compressor | air conditioning |
| air conditioning supplies | air courier service | aircraft |
| aircraft dealers | aircraft engine parts | aircraft engines manufacturers |
| aircraft engines parts manufacturers | aircraft equipment | aircraft equipment parts |
| aircraft equipment supplies | aircraft manufacturers | airline companies |
| airline services | airport | airport equipment |
| airport equipment manufacturers | airport supplies manufacturers | airport supply |
| alcoholic beverage | ale | alley |
| allied products | allied services | aluminum die casting |
| aluminum drawing | aluminum rolling | amusement |
| amusement parks | animal clinic | animal doctor |
| animal health | animal hospital | animal specialty services |
| ankle surgeons | antique jewelry | apartment building operators |
| apparel manufacturer | apparel trimmings | appliance dealers |
| appliance manufacturers | appliances repairing | architects |
| architectural metalwork | architectural services | armored car service |
| art gallery | artists fine arts | art school |
| asphalt coating | asphalt felts | assistants school |
| athletic goods | athletic organizations | attorney |
| auditing | auto cleaning detailing | auto dealers |
| auto detailing | automatic vending machines | automation equipment |
| automation equipment manufacturers | automation system | automation systems manufacturers |
| automobile | automobile body | automobile body painting |
| automobile body repairing | automobile dealers | automobile detail |
| automobile detail up service | automobile parking | automobile parts manufacturers |
| automobile parts rebuilt | automobile supplies manufacturers | automotive glass replacement shops |
| automotive repair shop | automotive transmission repair shops | automotive trimming |
| auto polishing | auto supply stores | auto transmissions |
| auto washing polishing |
