Sources to help you study the cluster and answer your research question are much the same as those that help you reconstruct the ancestor's cluster. Additional sources may be available for your ancestor's time and place. If you aren't familiar with state-specific choices, consult books about research in the ancestral state and books such as these:

• A Genealogist's Guide to Discovering Your Female Ancestors by Sharon DeBartolo Carmack (Betterway Books, $17.99)
• The Genealogist's Companion & Sourcebook by Emily Anne Croom (Betterway Books, $16.99)—Focuses on many kinds of US public sources.
• The Sleuth Book for Genealogists by Emily Anne Croom (Betterway Books, $18.99)—Case studies illustrate the value of the cluster approach, especially using census, land, probate, tax and court records.
• Ancestry's Red Book, revised edition, edited by Alice Eichholz (Ancestry, $49.95)—State-by-state guide to sources.
• Land & Property Research in the United States by E. Wade Hone (Ancestry, $49.95)
• U.S. Military Records: A Guide to Federal & State Sources by James C. Neagles (Ancestry, $39.95)