| 2021-05-23 | Massive ref. books |
| 2020-08-20 | Multivolume ref. works |
| 2019-01-06 | Ref. works that can run $1,000+ |
| 2017-09-28 | Library references, briefly |
| 2016-04-24 | Brit. reference sets |
| 2016-01-12 | Refs. that may occupy whole shelves |
| 2015-06-15 | Ref. books sometimes sold with magnifying glasses |
| 2014-10-09 | Meaningful sets, for short? |
| 2014-04-23 | Library refs. |
| 2012-06-13 | Ref. works sometimes sold with magnifying glasses |
| 2010-04-22 | Hefty refs. |
| 2009-12-20 | Lib. references |
| 2009-02-08 | They start A-B, C, D-E, etc. |
| 2007-04-18 | Multivolume refs. |
| 2004-11-28 | Ref. volumes |
| 2003-04-30 | Library refs. |
| 2002-08-05 | British refs. |
| 1998-03-02 | Multivolume ref. works |
| 1996-05-05 | English refs. |
| 1995-09-30 | Multivolume refs. |
| 1994-11-08 | Multivolume dicts. |