Richards, E. G..
Mapping time: the calendar and its history /
E.G. Richards 
. - Oxford : Oxford University Press,  1999 
. - xxi, 438 p.  tab., schem.  20 cm. 
<br/>К.: Бібліогр. : c. 411-428, Index 
<br/><label>  ISBN: </label>0-19-286205-7