“…There exists a 4-GDD of type 6 u m 1 for every u ≥ 4 and m ≡ 0 mod 3 with 0 ≤ m ≤ 3u − 3 except for (u, m) = (4, 0) and except possibly for (u, m) ∈ {(7, 15), (11,21), (11,24), (11,27), (13,27), (13,33), (17,39), (17,42), (19,45), (19,48), (19,51), (23,60), (23, 63)}. We also employ current existence results on 4-RGDDs.…”