aggregation

Bauman 2005


attribute

Burnard 1991, Vanhoutte 1998, Burnard 2014


attribute (global)

Burnard 2014


changing horses

Bauman 2005


class

Wittern et al. 2009


content model

Burnard 1991


decidability

Schmidt 2010


declaration

Burnard 1991


document type

Burnard 1991


DTD

Burnard 1991, Vanhoutte 1998, Vanhoutte 2004