A death notice is not an obituary, as it only gives the person's name, age, occupation (if known), and location and time of services. The key to using the online Tulsa World database is that the death must have occurred between 1989 and the present, as those years are the only ones included in the database. For prior years, you will need to visit to the Periodicals Department at the Central Library to make a microfilm copy.
A death notice usually appears the day after the death date. However, they can be up to two days later. An obituary may appear on the same day as a death notice, but usually it appears anywhere from a few days later to a week.