The legacy of Finnish-Estonian air ion and aerosol workshops - Kulmala, Markku; Horrak, Urmas; Manninen, Hanna E.; Mirme, Sander; Noppel, Madis; Lehtipalo, Katrianne; Junninen, Heikki; Vehkamäki, Hanna; Kerminen, Veli-Matti; Noe, Steffen M.; Tammet, Hannes (Boreal Environment Publishing Board, 2017)