Below is a small sample of open access non-textbook books in social work. Others may be found by searching Directory of Open Access Books or Oapen.
Social Work in Africa: Exploring Culturally Relevant Education and Practice in Ghana (E-book) by Note: Resources should also be searched by desired KEYWORD
These are ebooks that are available to your students for free through USM LIbraries' licensed content. They are not open source publications, and have standard copyrights, but they are available for use as texts.
Evidence-Based Practice in Clinical Social Work (E-book) by 
Social Justice Theory and Practice for Social Work: Critical and philosophical perspective (E-book) by 
Cultivating Mindfulness in Clinical Social Work (E-book) by 