Natural Medicines: https://naturalmedicines.therapeuticresearch.com/
Alt HealthWatch: http://uf.catalog.fcla.edu/permalink.jsp?20UF020571348
CAM on PubMed: https://nccih.nih.gov/research/camonpubmed (free)
IndMED: http://www.indmed.nic.in/ (free)
Index to Chiropractic Literature (ICL): https://www.chiroindex.org/#results (free)
General Information
National Center for Complementary and Integrative Health (NCCIH): https://nccih.nih.gov/research/statistics/NHIS
Trends in the Use of Complementary Health Approaches Among Adults: United States, 2002–2012: https://www.cdc.gov/nchs/data/nhsr/nhsr079.pdf
Use of Complementary Health Approaches Among Children Aged 4–17 Years in the United States: National Health Interview Survey, 2007–2012: https://www.cdc.gov/nchs/data/nhsr/nhsr078.pdf
Condition-specific
Complementary and Alternative Medicine Use by US Adults With Gastrointestinal Conditions: Results from the 2012 National Health Interview Survey: http://www.nature.com/articles/ajg2014108
Use of Complementary Health Approaches for Musculoskeletal Pain Disorders Among Adults:United States, 2012: https://www.cdc.gov/nchs/data/nhsr/nhsr098.pdf
Costs
Expenditures on Complementary Health Approaches: United States, 2012: https://www.cdc.gov/nchs/data/nhsr/nhsr095.pdf