1WHSP: An IR-based sample of ~1000 VHE γ-ray blazar candidates B. Arsioli, B. Fraga, P. Giommi, P. Padovani and P. M. Marrese A&A, 579 (2015) A34 Published online: 23 June 2015 DOI: 10.1051/0004-6361/201424148