Glassl, H. — Parnassius apollo. Seine Unterarten.

2005 (2nd ed.) 279 p., numerous coloured field photographs of specimens, 4 coloured folded maps, 4to, paperbound. Library stamps, else good copy. Includes about 296 regional forms and subspecies. All known subspecies are described. Species accounts include, description, distribution (with maps), habitat, flight time, foodplants.