Non-BPS D8-branes and Dynamic Domain Walls in Massive IIA Supergravities by A. Chamblin and others (1999, hep-th/9908047, 10.1088/1126-6708/1999/09/014)

Primary research paper. The abstract and introduction discuss D8-branes as domain walls of Romans massive IIA supergravity and matching between the two bulk regions.