We are cataloging one book "Todd & Wilson's text book on trusts" (11th ed.). Author is Sarah Wilson. But the original version was written by Paul Todd and published in 1991, the title was "Textbook on trusts". Starting from the 6th edition in , Sarah Wilson join the writing as a co-author in 2003. In 2005, when the 7th edition published, the title changed to "Todd & Wilson's text book on trusts" and only Sarah Wilson is listed in the title page. In the DLC records for 7th edition (OCLC: 58563014) and 8th edition (OCLC: 76935614), there is a name/title entry listed for Todd, Paul and previous edition. Starting from 2009, DLC records for 9th (OCLC: 277068200), and 10th edition (OCLC: 679931179), only Sarah Wilson is listed as the author. No 700 for Todd.
My question is whether Todd should still be listed as additional author considering his name is still in the title (But his name isn't listed on the title page or anywhere in the book)? If not, should 775 needed to link to the Todd's original work? (NOTE: this is the first RDA record among various edition. 7th and 8th edition has 700 name/title field for the previous edition based on the AACR2 rules, not 775.)