How many authors does 'A collaborative approach to heading estimation for smartphone-based PDR indoor localisation' have?
The paper 'A collaborative approach to heading estimation for smartphone-based PDR indoor localisation' has how many authors?
SELECT ?answer WHERE { <https://dblp.org/rec/conf/ipin/AbadiLHCN14> <https://dblp.org/rdf/schema#numberOfCreators> ?answer }
<https://dblp.org/rec/conf/ipin/AbadiLHCN14>