The following greats have all left this mortal coil;
Cal Wilson (1944-2018)
Del Bland (1933-2018)
JT Stanton (1952-2018)
Holland Wallace (1940-2018)
Cal Wilson ran one of the first and great numismatic book auctions and sales.
Del Bland was an expert on early
US Large Cents. He was best known as the co-author of the
US Large Cent Encyclopedia with Walter Breen. A fantastic reference book and one of the best reference books on the series to date.
JT Stanton co-author of the Cherrypickers Guides with Bill Fivaz
Holland Wallace the unknown hero of the
RedBook and Whitman publishing empire a top researcher of all world coins.
JT was a personal friend of mine, and I will miss his insights on error coins and varieties. JT and I met at an early 1980's
ANA Summer Seminar, he was a very knowledgeable person and very giving when it came to teaching others all about how errors and varieties are formed in the coin making process, he also took amazing photographs (starting in the pre digital era) for all of us to learn from. Many of his photographs are in the Mega Red Coin Book. He is greatly missed by many in the coin business.

For much more insight see the Vol. 21 Issue #43 of E-Sylum at coinbooks.org (should be active in a few days if you aren't already on the mailing list).
"Buy the Book Before You Buy the Coin" - Aaron R. Feldman - "And read it" - Me 2013!
ANA Life Member #3288 in good standing since 1981, ANS, Early American Coppers Member (EAC), Colonial Coin Collectors Club member (C4), Conder Token Collector Club member (CTCC), Civil War Token Society (CWTS) member, Liberty Seated Collectors Club (LSCC) & Numismatic Bibliomania Society member (NBS), USMex, Member in good standing, 2¢ variety collector.
See my want page:
http://goccf.com/t/140440