In this work, coincidence summing correction factors have been measured for 133Ba, 152Eu and 88Y point sources with a 50% relative efficiency p-type detector and a 25% relative efficiency n-type detector in two close-to-detector measurement geometries. The experimental data for 133Ba and 152Eu and the results obtained with the GESPECOR software reveal a complex structure of the conventional dead layer of the p-type detector. The high value of the coincidence summing correction factor for the 511 keV peak of 88Y, in agreement with the values computed by GESPECOR, in this case cautions against the application of the semiempirical method for evaluating coincidence summing effects.