Tapani Raiko Alexander Ilin Juha Karhunen Principal Component Analysis for Sparse High-Dimensional Data. 566-575 2007 ICONIP (1) http://dx.doi.org/10.1007/978-3-540-69158-7_59 conf/iconip/2007-1 db/conf/iconip/iconip2007-1.html#RaikoIK07