The publisher, Walter Lehning, lists this book as a Liliput mini-comic, but as you surmise, it is larger than the earlier Liliiput Fulgor, Akim, Blauwe Pijl, and Jezab single-tier 1 or 2-panel, horizontally-oriented mini-comics. It is also larger than the taller than Fulgor 1st series, Dolf Staal Spar Supermarkt series. This 2nd Fulgor, vertically-oriented, full-colour series seems to be about 65% as large as normal vertically-oriented European comic books of that time, which were fairly close to the size of US normal comic books of the 1950s, except a bit narrower, but a littler taller. So, in being that much smaller, they qualified as mini-comics, but were a fair amount larger than Fulgor 1st one-tier series. The writer and artist was the well-known German artist, Hansrudi Wascher, the writer and artist of Siguurd (The German clone of Prince Valient). I guess The Italian publisher hired Wascher to draw Fulgor 2nd Series, as Augusto Pedrazza was no longer available.
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Fulgor series 2 - 3 - Piraten In Het Wereldruim