Swecon was in Stockholm and Joe Haldeman , Geoff Ryman, Martin Andreasso were part of Imagicon.
[['[TABLECONTEXT]', '[TITLE]', 'Swecon'], ['Imagicon', 'GUEST(S)_OF_HONOUR', 'Joe Haldeman, Geoff Ryman, Martin Andreasson'], ['[TABLECONTEXT]', 'NAME', 'Imagicon'], ['Imagicon', 'LOCATION', 'Stockholm']]