| Title | Author | Publication | Date | Pages | Comments |
| Ultramar Overprints | Hart, Albert J. | Oxcart | Dec 1999 | 123-125 | Talks about Costa |
| - An Update | Rica but were also |
| Un Proceso Judicial, | anon | Revista de la | 16-20 | Bogus "hi values" |
| con motivo de la | Sociedad Filatelica |
| Un Real, Paraguay, | Caillebotte, G. | Philatelic Record | Feb 1884 | 26 | Questions |
| Surcharged "5" | authenticity of |
| Unbekanntes aus | Zimmer, Dr. | Die Ganzsache | 1982 | 104-107 | Postcard & cancel |
| Sudamerika |
| Urbanismo Colonial | Munoz, Francisco | Atalaya Filatelica | Apr 1996 | 33-35 | Foundations of |
| Espanol en America | Basallote | Towns |
| Vain Australian | anon | Stamp News | Mar 1981 | 16-21 | Colony |
| Search For Utopia in | (Australia) |
| Vain Australian | anon | Stampnews | Mar 1981 | 17-21 | Colonies |
| Search for Utopia in | (Australia) |
| Valores altos de la | Godoi, Juansilvano | Apuntes Filatelicos | No. 36 | 10-11 | Varieties |
| emision ordinaria de |
| Varia | anon | Philatelic Record | Jan 1892 | 17 | Benjamin, Sarpy, |
| Jeffryes |
| Variedades del | anon | Revista de la | 172 | Varieties |
| Paraguay | Sociedad Filatelica |
| Vuelos del "Graf | Saavedra, Alfredo | Chile Filatelico | Mar 1974 | 9-12 | Zepp flights |
| Zeppelin" a |
| Western Hemisphere | Bloss, A. W. | Stamps | Dec 23, 1950 | 450 | Cancellations |
| Notes: Latin |
| What about | Oatway, E.E. [letter] | Philatelic Exporter | 28 | Unnecessary issues |
| Paraguay? |
| World Airmail | anon | Sanabria CATALOG | 1966 | 948-981 | Stamp & proofs |
| Catalogue |
| Zeppelin Cachets - | anon | Stamp Collecting | Jul 28, 1930 | 404 | Unofficial cachet |
| Paraguay |
| Zeppelin Postal | anon | http://www.total.net/ | 1998 | Web listing |
| Markings | ~revans/markings.ht |
| Zeppelin Posts | anon | American Airmail | 1974 | 282-305 | Zepp info |
| Catalogue |
| Zeppelinpost | anon | Corinphila Auction | Oct 29, 1999 | 17+ pictures | Paraguay Zepps |
| Zur Nachdruckfrage | anon | Illustriertes | Dec 21, 1912 | 610 | Quotes decree for |
| der ersten | Briefmarken Journal | issue |
| Zur Nachdruckfrage | Schnitzler, Julius | Illustriertes | Oct 5, 1912 | 468-470 | Questions if there is |
| von Paraguay | Briefmarken Journal | a reprint |
| Saturday, February 19, 2000 | Page 42 of 42 |