Hans Hanan Wellisch (April 25, 1920 - February 6, 2004) was a librarian, LIS educator, and indexer known for his work with the International Federation for Documentation (later International Federation for Information and Documentation), contributing to the Universal Decimal Classification.^[1] He headed the committee which translated the abridgement of the UDC into Hebrew and was the compiler of the index to the system.^[2]

Wellisch graduated from high school and was arrested in November 1938, and sent to Dachau concentration camp.^[1][3] When arrested he already had a visa to Sweden, so he was sent there after two and a half months.^[1] There he briefly worked in the special library of the Swedish Cooperative Federation which gave him some training in librarianship.^[1] He emigrated to Israel in 1949 where he was the librarian of the Signal Corps of the Israel Defense Forces.^[1] He received a grant from the United Nations to study at the University of Maryland in 1967. The university invited him to join the School of Library Science as a visiting lecturer two years later.^[2] He worked there for the rest of his professional career, and earned a Masters in Library Science in 1972 and a Ph.D. in 1975.^[2] He retired from UMD in 1989 as a full professor.^[2]

He was the first recipient of the American Society for Indexing Award for the index to his book, The Conversion of Scripts: Its Nature, History and Utilization.^[2] He also won the Hines Award for "continuous dedicated and exceptional service" to the ASI where he was president from 1984 to 1985.^[2]

Wellisch was born in Vienna.^[1] He was married to Shulamith Wellisch, and the couple had three children Tamar, Ilana and Yuval Wellisch.^[4]

• Wellisch, H. H. (1975). Transcription and transliteration: An annotated bibliography on conversion of scripts. Silver Spring, Md: Institute of Modern Languages.
• Wellisch, Hans (Hanan) (June 1975). "Conrad Gessner: a bio-bibliography". Journal of the Society for the Bibliography of Natural History. 7 (2): 151–247.
• Wellisch, H. H. (1976). “Relative Importance of the World’s Major Scripts.” Libri: International Journal of Libraries & Information Services 26 (September): 238–50.
• Wellisch, Hans H. (1977). The PRECIS index system: principles, applications, and prospects : proceedings of the International PRECIS Workshop, October 15–17, 1976. New York: Wilson.
• Wellisch, H. H. (1978). The conversion of scripts, its nature, history, and utilization. New York: Wiley.
• Wellisch. Hans H. (1978). “Script Conversion and Bibliographic Control of Documents in Dissimilar Scripts: Problems and Alternatives.” International Library Review 10 (January): 3–22.
• Wellisch, Hans H. (1980). “Bibliographic Access to Multilingual Collections.” Library Trends 29 (October): 223–44.
• Wellisch, H. H. (1980). Indexing and abstracting: An international bibliography. Santa Barbara, Calif: ABC-Clio.
• Wellisch, Hans H. (1981). “Ebla: The World's Oldest Library.” The Journal of Library History 16, no. 3, 1981, pp. 488–500.
• Wellisch, Hans H. (1983). “ALA Filing Rules: Flowcharts Illustrating Their Application, with a Critique and Suggestions for Improvement.” Journal of the American Society for Information Science 34 (September): 313–30.
• Wellisch, H. H., & Gessner, C. (1984). Conrad Gessner: A bio-bibliography. Zug, Switzerland: IDC.
• Wellisch, Hans, H. (1986). "The Oldest Printed Indexes." The Indexer 15 no 2 October., pp. 1–10.
• Wellisch, Hans H. (1986). The First Arab Bibliography : Fihrist Al-ʻUlum. Occasional Papers / University of Illinois, Graduate School of Library and Information Science: No. 175. Board of Trustees of the University of Illinois.
• Wellisch, Hans H. (1991). Indexing from A to Z. Bronx, N.Y.: H.W. Wilson.
• Wellisch, Hans H. (1994). “Incunabula Indexes.” Indexer 19 (April): 3–12.
• Wellisch, Hans H. (1998) "Cultivating the Garden of Librarianship". Cataloging & Classification Quarterly, 25:4, 289-304.