Hopkins, Ralph L. <br/><br/>
Synthesis of cyclic sulfides  
Hopkins, Ralph L. 
 - Washington  Bureau of mines  1967 
 - Report Investigation  6970 .
<br/><br/><label>Subjects--Topical Terms: </label><br/>sulfuros cíclicos
<br/><br/><label>Universal Decimal Class. No.: </label>549.3 :543.632.532.3 (47)