I found this a few years ago in the 1978 edition of Burnham's (Burnbaum's) Celestial Handbook Vol. II, page 754, third paragraph: "Albireo is believed to be a physical pair, although no evidence of ortibal motion has been detected since the first observations of F.G.W. Struve in 1832."
Orbit diagram - Sixth Catalogue of the Orbits of Visual Binary States http://ad.usno.navy.mil/wds/orb6/PNG/wds19307+2758a.png Sixth Catalogue of the Orbits of Visual Binary States Data - search for "19307+2758" - 213.8 year orbit http://ad.usno.navy.mil/wds/orb6/orb6orbits.html Sixth Catalogue COlumn descriptions http://ad.usno.navy.mil/wds/orb6/orb6text.html#description Orbit study that is the basis for the 6th Orbit Catalogue Entry http://adsabs.harvard.edu/abs/2008AN....329...54S The CCDM lists Albireo as a triple http://vizier.u-strasbg.fr/viz-bin/VizieR?-source=I/274 Wikipedia entry http://en.wikipedia.org/wiki/Albireo Albireo as a Triple Star (Haven't pulled this one) Webb, T. W.; McAlister, H. A.; Worley, C. E.; Burnham, S. W.; Aitken, R. G. SKY AND TELESCOPE V. 59, P. 210, 1980 (S&T Homepage) http://adsabs.harvard.edu/abs/1980S&T....59..210W Clear skies - Kurt