@book{ReedSimon1,
   maintitle =    {Methods of Modern Mathematical Physics},
   title =     {Functional Analysis},
   author =    {Michael Reed and Barry Simon},
   publisher = {Academic Press},
   date =      {1980},
   edition = {Revised and Enlarged Edition},
   volume =    {1},
}
@book{ReedSimon2,
   maintitle =    {Methods of Modern Mathematical Physics},
   title =     {Fourier Analysis, Self-Adjointness},
   author =    {Michael Reed and Barry Simon},
   publisher = {Academic Press},
   date =      {1975},
   volume =    {2},
}
@article{Nelson1972,
 title     = {Time-Ordered Operator Products of Sharp-Time Quadratic Forms},
 author    = {Edward Nelson},
 publisher = {Elsevier Science},
 journal   = {Journal of Functional Analysis},
 issn      = {0022-1236,1096-0783},
 date      = {1972},
 volume    = {11},
 number     = {2},
 pages     = {211--219},
}