the NOT. Narrow-band photometry data from the literature was used to distinguish between O-rich and C-rich stars.]{} [We report the detection of 513 LPVs in and 213 LPVs in , showing amplitudes $\Delta i$ of up to $\approx$2$^{\rm mag}$ and periods ranging between 90 and 800 days. The period-luminosity diagram for each of our target galaxies exhibits a well populated sequence of fundamental mode pulsators. The resulting period-luminosity relations we obtained are compared to relations from the literature. We discuss the universality of those relations because of which, as a side result, a correction of the distance modulus of may be necessary. A value of ($m$–$M$)=$24\fm30$ seems to be more appropriate to match the observed data. Only one of our two galaxies, namely , has a significant fraction of possibly first overtone pulsators. An interpretation of this finding in terms of differences in the star-formation histories is suggested. ]{}

Introduction {#s:intro}
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Asymptotic Giant Branch (AGB) stars are highly evolved stars with low to intermediate initial masses of $\approx$$0.6-8 M_{\odot}$ that have passed the helium-core burning phase. These stars are then powered by nuclear burning of hydrogen and helium in two thin shells on top of a core of carbon 