Pauk, Walter.
Clarifying devices : level C : one hundred passages with questions for developing concentration and the skill of understanding clarifying devices, one of the six essential categories of comprehension /

. - Lincolnwood  : Jamestown Publishers,  1985 
. - 63 p.  23 cm. 
 - (Single skills )
<br/><label>  ISBN: </label>0-89061-368-0