2026-10-04 — Book records (AbeBooks/Goodreads/Amazon via Google) and Bentham Books

Queries: Google "Elementary Antigravity" Znidarsic 1989 Vantage OR publisher OR ISBN; Google "Gravity-Superconductors Interactions" Bentham Robertson "Type II superconductor" gravitational waves.

Findings [web]

• "Elementary Antigravity", Frank Znidarsic, Vantage Press, New York, 1989, 53 pp., ISBN 0-533-08334-6 / 978-0-533-08334-3 (AbeBooks https://www.abebooks.com ; GetTextbooks; library-style record quoted on fliphtml5). Copies listed at $142-$195. Vantage Press was a subsidy (author-paid) publisher [memory, high]. The NPA wiki states "Elementary Antigravity II" (2012) follows it and the first edition sold out.
• Goodreads lists 2 books; Amazon has an author page; AbeBooks lists "Energy, Cold Fusion, & Antigravity: Znidarsic Science Books". Facebook profile links to http://www.angelfire.com/scifi2/zpt/zptblog.html ("Znidarsic Science Books") — not visited.
• Robertson's chapter cited as "planned 2011" in The Flow of Energy (ref. 7) was published: G. A. Robertson, "Quantum Effects in the Type II Superconductor that Lead to Power Radiated in Gravitational Waves", in G. Modanese & G. A. Robertson (eds.), Gravity-Superconductors Interactions: Theory and Experiment, Bentham Science, 2012 (benthambooks.com; eurekaselect.com; paywalled, $119). It is cited by A. Gallerati et al., "Interaction between macroscopic quantum systems and gravity", Frontiers in Physics 2022 (fphy.2022.941858), i.e. a later mainstream-journal review in this area cites the Robertson line of work. Not read. (A dokumen.pub copy appears in results; not used — likely unauthorized.) Bearing: claim 4 (Josephson-junction scale and Robertson's electron-pair frequency, unpublished at the time of the 2011 paper) and claim 6; the 1989 book is the earliest statement of his antigravity programme. Recheck: yes (obtain the 1989 book contents via a library/WorldCat; Robertson chapter abstract).