digraph  {
node [shape=box, fontname="Helvetica Neue Light", fontsize=10];
edge [fontsize=8, fontname="Helvetica Neue Light", penwidth=.5, arrowsize=.6];

Questionnaire -> Pages [label="has a set of"]
Pages -> Questions [label="has a list of"]
Pages -> Instruments [label="can include"]
Instruments -> Questions [label="has a list of"]
Questions -> ChoiceSet [label="can reference"]
}
