Including these sources:
- abs energy research
- access intelligence llc d/b/a pbi media, llc
- computer industry almanac, inc.
- enerdata
- ie market research corp.
- institute of real estate management
- international council of shopping centers
- international marketing reports ltd.
- marketline, a datamonitor business
- nrg expert
- richard k. miller & associates
- sanford c. bernstein & co., llc
- t3i group llc