Where can I find Defense strengthening in Quierschied?

Defense strengthening can also be found in these cities:

Bous Dillingen (Saar) Illingen Marpingen Neunkirchen Püttlingen Saarbrücken Saarlouis Saarwellingen Sankt Ingbert Sankt Wendel Schmelz Schwalbach Spiesen-Elversberg

You can also find this in Quierschied:

Edible Curd Grated Lemon Peel Flaxseed Bread Fruit Bar Pickled Vegetables Fresh Salt Schupfnudeln Whole Grain Rolls Mayonnaise