  The number of discovered non-radially pulsating white dwarfs (WDs) in
cataclysmic variables (CVs) is increasing rapidly by the aid of the Sloan
Digital Sky Survey (SDSS). We performed photometric observations of two
additional objects, SDSS J133941.11+484727.5 (SDSS 1339), independently
discovered as a pulsator by Gansicke et al., and SDSS J151413.72+454911.9,
which we identified as a CV/ZZ Ceti hybrid. In this Letter we present the
results of the remote observations of these targets performed with the Nordic
Optical Telescope (NOT) during the Nordic-Baltic Research School at Moletai
Observatory, and follow-up observations executed by NOT in service mode. We
also present 3 candidates we found to be non-pulsating. The results of our
observations show that the main pulsation frequencies agree with those found in
previous CV/ZZ Ceti hybrids, but specifically for SDSS 1339 the principal
period differs slightly between individual observations and also from the
recent independent observation by Gansicke et al. Analysis of SDSS colour data
for the small sample of pulsating and non-pulsating CV/ZZ Ceti hybrids found so
far, seems to indicate that the r-i colour could be a good marker for the
instability strip of this class of pulsating WDs.
