The single largest database with NIR data on Cepheids is [29, Laney & Stobie (1992)] who provide data for 51 Cepheids on the Carter system. Intensity-mean magnitudes have been calculated by me following the recipe outlined above, and agree exactly or within one unit in the last decimal with the number published by them.
The other two datasets used are [42, Welch et al. (1984)] and
[6, Barnes et al. (1997).] Both provide magnitudes in the CIT system and these have
been converted to the Carter system using the formula in Table 3 of
[30, Laney & Stobie (1993).] From Welch et al., only stars with 
points in the light curve have been considered. This leaves out as
many as about 40 stars, but with 2-5 points in the light curve no
sufficiently accurate (that is at a level of 0.01 mag) intensity-mean
(or magnitude-mean) can be determined.
Data from the following sources is not considered: [31, Lloyd Evans (1980)] because of large error in individual measurements (> 0.06 mag); [32, McGonegal et al. (1983)] and [35, Schechter et al. (1992),] because they observed only few points in the light curve; [22, Fernley et al. (1989)] because of the photometric system.
The intensity-mean JHK magnitudes are listed in Table 4. It contains 89 determinations for 69 stars. When more than one dataset exists, they are listed in the following order: [29, Laney & Stobie (1992),] [6, Barnes et al. (1997),] [42, Welch et al. (1984).] This can be thought of as an order of preference, prefering the largest single dataset in the Carter system over the other two sources of photometry which had to be transformed from the CIT to the Carter system, and then prefering [6, Barnes et al. (1997)] over [42, Welch et al. (1984)] because their light curves contain more data points.
In about a dozen cases there is photometry available from 2 or more sources. Comparing the datasets suggests consistency at a level of 0.01 magnitudes, although larger differences (up to 0.04 mag) exist.
Acknowledgements
This research has made use of the SIMBAD database, operated at CDS, Strasbourg, France.
Copyright The European Southern Observatory (ESO)
