From Queenpedia.com

Release information Release date Catalog number Country 7" Singles dd/06/1976 EMI2494 UK dd/mm/1984 G451 UK dd/mm/1976 4C 006-97944 Belgium dd/mm/1976 1C00697944 Germany dd/mm/1976 5C006-97944 Holland dd/mm/1976 3C006-97944 Italy dd/mm/1976 P-16E Japan dd/mm/1976 1J 006-97944 Spain dd/mm/1976 Thailand dd/05/1976 E-45318 USA dd/05/1976 E-45318 USA dd/05/1976 E-45318 USA dd/mm/1976 SEMI88908 Yugoslavia 7" Promos 1976-xx-xx E-45318 USA

Tracklists 7" Tracklist Side A: You're My Best Friend Side B: '39 1984 UK 7" re-release Side A: Killer Queen Side A: You're My Best Friend Credits Produced by: Queen and Roy Thomas Baker Charts Bold indicates peak chart position. Country 1st chart appearance Chart run Weeks in chart UK 03/07/1976 24-15-7-8-10-16-24-30 8 (3 in Top 10) USA 22/05/1976 78-66-46-32-27-23-21-20- 18-17-16-16-24-39-42-59 16 Notes The USA had 4 different label variations.