All available minima times of GW Car are listed in Table 2. The weights
of the photographic minima times were adopted from the work of O’Connell
(1956) except for the minimum JD2433121.743, which was omitted from our
further analysis. We calculated the weights od photoelectric minima using the
procedure as described in the subsection 2.1., but we used for normalization
of the photoelectric weights the mean photographic weight w = 6 instead of
the weight equal one. Our analysis of the data showed considerable difference
between the linear ephemerides found from the photografic and photoelectric
minima times taken in 1935-1954 and 1969-81, respectively. Therefore, we used
only the photoelectric minima times for determination of the light elements (by
the least-squares method):