Group divisible designs with block size four and group type where is a multiple of 8

We determine, up to some possible exceptions, the spectrum for 4-GDDs of type g u m 1 , where g is a multiple of 8 until 48, g is a multiple of 24 until 144, respectively. These spectra are without exceptions for g = 8 , 16, 24, 48, 72, 96, 120 and 144. Furthermore, we establish, up to a finite number of possible exceptions, the spectra for 4-GDDs of types 3 0 u m 1 and 9 0 u m 1 . Finally, we provide nine {3, 5}-URDs which were the last possible exceptions in their classes.