Mention the number of authors of the paper 'Combining tactile sensing and vision for rapid haptic mapping'.
How many authors does the publication 'Combining tactile sensing and vision for rapid haptic mapping' have?
SELECT ?answer WHERE { <https://dblp.org/rec/conf/iros/BhattacharjeeSP15> <https://dblp.org/rdf/schema#numberOfCreators> ?answer }
<https://dblp.org/rec/conf/iros/BhattacharjeeSP15>