Sources and References:

  1. Iso-Heikkilä - Wikipedia: Iso-Heikkilä (Finnish; Storheikkilä in Swedish) is a district of the city of Turku, in Finland. It is located to the west of the city centre, bordering on the city centre's ...
  2. Iso-Heikkilä Observatory - Wikipedia: Iso-Heikkilä Observatory (Finnish: Iso-Heikkilän tähtitorni) is an amateur astronomical observatory used by a local amateur astronomical association, Turun Ursa ...
  3. ISO/TC 138 - Plastics pipes, fittings and valves for the ... - ISO: ISO/TC 138/SC 1, Plastics pipes and fittings for soil, waste and drainage ( including ... ISO/TC 138/SC 5, General properties of pipes, fittings and valves of plastic ...
  4. LK: For the simpler, smarter everyday: Today operating on a global scale within the areas of heating and plumbing ... LK strengthens its sustainability work and creates clarity with new ISO standards.