You simply need to block the pages via <block> or <survey> elements, then randomize those blocks at the <expt> level. E.g., suppose you have two questionnaires 'qa' and 'qb', each comprising two pages 'p01' and 'p02', then
<block qa>
/ trials = [1=qa_p01; 2=qa_p02]
</block>
<block qb>
/ trials = [1=qb_p01; 2=qb_p02]
</block>
<expt>
/ blocks = [1-2=noreplace(qa,qb)]
</expt>
or (for separate data files per <survey>)
<survey qa>
/ pages = [1=qa_p01; 2=qa_p02]
</survey>
<survey qb>
/ pages = [1=qb_p01; 2=qb_p02]
</survey>
<expt>
/ blocks = [1-2=noreplace(qa,qb)]
</expt>
You may even take it one step further randomize the pages withing each questionnaire in addition:
<survey qa>
/ pages = [1-2=noreplace(qa_p01,qa_p02)]
</survey>
<survey qb>
/ pages = [1-2=noreplace(qb_p01,qb_p02)]
</survey>
<expt>
/ blocks = [1-2=noreplace(qa,qb)]
</expt>
Regards,
~Dave