@nami: Yes, that's right. The history of the series' publishing dates is pretty interesting, actually.
- The first chapter was serialized in December 1985.
- It came back in January 1987 and ran semi-regularly in Monthly Shonen Jump until July 1992 (eight chapters serialized, with a new chapter roughly every 6-12 months).
- There was one special chapter in February 1995.
- Then it came back in February 2001 and had a second semi-regular run until September 2004 (seven chapters serialized, this time with 4-6 month gaps between them).
- There was another special chapter in July 2007.
- It made another return almost 10 years later in March 2017, this time running in Jump Sq. (three chapters serialized, with a roughly 6 month gap between them).
- Lastly, it switched to Jump Sq. Rise in May 2018, (where it is still ongoing, currently at 12 chapters serialized, released seasonally, as the magazine is only released 4 times per-year).
Overall, the current chapter count is 33, and the first 30 of those have been collected into 9 volumes.