Hours of work in coal mines.  Item II on the agenda. 

 - Geneva,  International labour office,  1930. 
 - 91, [1] p.  21 cm. 
<br/><br/> At head of title: Questionnaire. International labour conference. Fifteenth session. Geneva--May, 1931. 
<br/><br/><label>LCCN: </label>l  31000028  
<br/><br/><label>Subjects--Topical Terms: </label><br/>Coal mines and mining.<br/>Hours of labor.<br/>Coal miners.
<br/><br/><label>LC Class. No.: </label>HD5119.M6  / I5 1930b 
<br/><br/><label>Dewey Class. No.: </label>331.8182233