a   This measurement was made with no filter.
b   This measurement was done with a Schott RG610 blocking filter.
c   This measurement was done with no filter and an EMI 9781B 
c   photomultiplier.
d   This measurement of the tertiary did not determine a Delta-m.
e   This measurement used a RCA 4526V1 photomultiplier and a Schott VG
e   9 filter.
f   This measurement used a RCA 4526V1 photomultiplier and a
f   combination of Schott BG 12 and GG 15 filters.
g   This measurement used a RCA 1P21 photomultiplier and a Schott BG
g   1 filter.
h   This measurement used a RCA 4526V1 photomultiplier and a Schott BG
h   12 filter.
i   This measurement has an unknown passband.
j   This measurement had no theta vector direction, Delta-m, or
j   passband determined.
k   This measurement used a EMI 6256S photomultiplier and no filter.
l   This measurement was specified as using a blue filter. The exact
l   passband is unknown.
m   This measurement has an unknown passband, although it is specified
m   as being in the 1.6 - 3.5 micron infrared range.
n   This measurement was done with a Schott BG 14 filter. A plot of
n   transmission characteristics is given in Bringans et al. (1974),
n   but was for a different photomultiplier.