Robinson, Spider. <br/><br/>
Callahan's crosstime saloon / 
by Spider Robinson. 
 - New York, N.Y. :  Ace Science Fiction Books,  1977. 
 - xix, 170 p. 
<br/><br/><label>ISBN: </label>0441090699 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Fiction--Science fiction--General.