It released six new installments from November 2008 to August 2016 .
Tor Books , an imprint under Macmillan Publishers , currently publishes the series in both print and e-book format .
Tor Books released six new installments from November 2008 to August 2016 .
Tor Books , an imprint under Macmillan Publishers , currently publishes the series in both print and e-book format .