Sources of figures

Figure Two pools with sequence and message flow:

Business Process Modeling Notation, Working Draft (1.0); BPMI.org; August 25, 2003; page 85.

Figure Pool with two lanes according to BPMN:

Business Process Modeling Notation, Working Draft (1.0); BPMI.org; August 25, 2003; page 87.

Figure Event categories and figure Examples of event types:

Business Process Modeling Notation, Working Draft (1.0); BPMI.org; August 25, 2003; page 27.

Figure Activities according to BPMN:

Business Process Modeling Notation, Working Draft (1.0); BPMI.org; August 25, 2003; page 28.

Figure Gateway types:

Business Process Modeling Notation, Working Draft (1.0); BPMI.org; August 25, 2003; page 28.