Parker, John. <br/><br/>
Cross numbers / 
by John Parker. 
 - Norfolk :  Tarquin,  2004. 
 - 32 p. :  30 cm. 
<br/><br/><label>ISBN: </label>0906212952 
<br/><br/><label>Subjects--Topical Terms: </label><br/>Mathematical recreations.