Axhausen, Kay W. and Boltze, Manfred and Polak, John W. and Puzicha, Jörg (1994):
Effectiveness of the Parking Guidance System in Frankfurt am Main.
In: Traffic Engineering + Control, 35 (5), pp. 304-309, ISSN 0041-0683,
[Online-Edition: http://www.verkehr.tu-darmstadt.de/media/verkehr/fgvv/prof_b...],
[Article]

Boltze, Manfred and Axhausen, Kay W. and Polak, John W. and Puzicha, Jörg (1994):
Parkverhalten und Wirksamkeit des Parkleitsystems in Frankfurt am Main.
In: Straßenverkehrstechnik, 38 (5), Bonn-Bad Godesberg : Kirschbaum-Verlag, pp. 29-34, ISSN 0039-2219,
[Online-Edition: http://www.verkehr.tu-darmstadt.de/media/verkehr/fgvv/prof_b...],
[Article]

Boltze, Manfred and Axhausen, Kay W. and Polak, John W. (1993):
Effectiveness of Parking Guidance and Information Systems: Recent Evidence from Nottingham and Frankfurt am Main.
In: Compendium of Technical Papers, Annual Meeting of the Institute of Transportation Engineers, 19. bis 22. September 1993, Den Haag, pp. 109-113, [Online-Edition: http://www.verkehr.tu-darmstadt.de/media/verkehr/fgvv/prof_b...],
[Book Section]