Norton, James <br/><br/>
Introduction :  symposium on industrial minerals of the upper Midwest discussion and reply 

<br/><br/>bibliogr. p. 559 
<br/><br/><label>ISSN: </label>00167606 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Substance utile<br/>Economie minière<br/>Production<br/>Evaluation gîte
<br/><br/><label>Subjects--Index Terms: </label>Etats Unis