Background sources help broaden an understanding of a topic and expose you to new/different terminology that will be useful in searching databases or the web. Formats include encyclopedias, handbooks, and other reference materials.
Encyclopedia of Family Studies by 
Handbook of Family Literacy by 
Handbook of Family Theories by 
Handbook of Feminist Family Studies by 
International Encyclopedia of Social and Behavioral Sciences by
Fully revised and updated, the second edition of the International Encyclopedia of the Social and Behavioral Sciences, first published in 2001, offers a source of social and behavioral sciences reference material that is broader and deeper than any other. Available in both print and online editions, it comprises over 3,900 articles, commissioned by 71 Section Editors, and includes 90,000 bibliographic references as well as comprehensive name and subject indexes. Provides authoritative, foundational, interdisciplinary knowledge across the wide range of behavioral and social sciences fields Discusses history, current trends and future directions Topics are cross-referenced with related topics and each article highlights further reading
The Oxford Handbook of Work and Family by 
The Social History of the American Family by 