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  Category:Barbituric acid – Wikimedia Commons

  https://commons.wikimedia.org/wiki/Category:Barbituric_acid?uselang=de

  Keine Beschreibung vorhanden.

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  EU Pesticides database - European Commission

  http://ec.europa.eu/food/plant/pesticides/eu-pesticides-database/public/?event=activesubstance.detail&language=DE&selectedID=1843

  is the reference database for member states about the pesticide residues, active substances and products and their values

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  Category:Urea – Wikimedia Commons

  https://commons.wikimedia.org/wiki/Category:Urea?uselang=de

  Keine Beschreibung vorhanden.

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  Category:Acid-base reactions – Wikimedia Commons

  https://commons.wikimedia.org/wiki/Category:Acid-base_reactions?uselang=de

  Keine Beschreibung vorhanden.

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