@article{10_1017_S0008439500031477,
     author = {Alexander, J. C.},
     title = {Introduction to {Spectral} {Theory} in {Hilbert} {Space,} by {G.} {M.} {Helmberg.} iii + 346 pages. {Series} in {Applied} {Mathematics} and {Mechanics,} {North-Holland,} {Amsterdam,} 6, 1969. {U.S.} $19.50.},
     journal = {Canadian mathematical bulletin},
     pages = {461--462},
     year = {1972},
     volume = {15},
     number = {3},
     doi = {10.1017/S0008439500031477},
     url = {http://geodesic.mathdoc.fr/articles/10.1017/S0008439500031477/}
}