HTFS was part of (now part of Aspen Plus / Aspen Exchanger Design & Rating). Handbooks contain:
18;write_to_target_document1a;_I7Huae3iJ9mFw8cP8Jup6AU_20;56; 0;f0c;0;7ba; The HTFS Handbook htfs handbookrar work
: Officially, the handbook and its associated software (like Aspen EDR ) are proprietary and available only to paying members or corporate subscribers. HTFS was part of (now part of Aspen