1. Brochure Solar Heat for Industry, Editors Bärbel Epp, Marisol Oropeza, https://www.solar-pay.com/wp-content/uploads/2017/07/Solar-Heat-for-Industry-Solar-Payback-April-2017.pdf.
2. SHIP Supplier Surveys 2018 and 2019 carried out by solrico within the Project Solar Payback, https://www.solartherm.org/keyword/olarpayback.
3. World´s largest solar district heating plant with concentrating collector, Bärbel Epp, https://www.solartherm.org/news/worlds-largest-solar-district-heating-plant-concentrating-collectors.
4. Durability Studies of Solar Reflectors Used in Concentrating Solar Thermal Technologies under Corrosive Sulfurous Atmospheres
5. HiFlex project website http://hiflex-project.eu/.