"1998"^^ . . "1998 IPBC International pulp bleaching conference 1, oral presentations : proceedings : June 1-5, 1998, Helsinki Fair Centre, Helsinki, Finland / KCL, PI / [Helsinki (Finlande)] : [Gummerus Kirjapaino Oy] , 1998, cop. 1998" . . "0"^^ . . . . . . . .