I ran a search on amazon.com and amazon.co.uk and turned up these:
http://www.amazon.com/gp/search/ref=sr_adv_b/?search-alias=stripbooks&unfiltered=1&field-keywords=&field-author=&field-title=The+Imperial+German+regimental+marking&field-isbn=&field-publisher=&node=&field-p_n_condition-type=&field-feature_browse-bin=&field-binding_browse-bin=&field-subject=&field-language=&field-dateop=&field-datemod=&field-dateyear=&sort=relevancerank&Adv-Srch-Books-Submit.x=36&Adv-Srch-Books-Submit.y=10
and
http://www.amazon.co.uk/gp/offer-listing/B0006S4H6Y/ref=sr_1_olp_1?ie=UTF8&s=books&qid=1266458428&sr=1-1&condition=used
Good luck.
Cheers,
Laurie