 Date's most recent reflections can be found on the Web at Date (1999), "The Database Relational Model" (2001) and "Date on RM/T" (2003).RM/T contributed to the body of knowledge called semantic data modeling and semantic object modeling and continues to influence new data modellers.See the paper by Hammer and McLeod (1981), the book by Knoenke (2001) and implementation by Grabczewski et alia (2004).