National Polytechnical Museum
... that the National Polytechnical Museum in Sofia holds the only Bulgarian-manufactured Hammond organ?
... that the <b id="mwBn0"><a href="./National_Polytechnical_Museum" id="mwBn4" rel="mw:WikiLink" title="National Polytechnical Museum">National Polytechnical Museum</a></b> in <a href="./Sofia" id="mwBn8" rel="mw:WikiLink" title="Sofia">Sofia</a> holds the only Bulgarian-manufactured <a href="./Hammond_organ" id="mwBoA" rel="mw:WikiLink" title="Hammond organ">Hammond organ</a>?