Content Type OA ? PCA ? Books (Back List, Front List) Yes N/A Request a holdings comparison Portico provides a free holdings comparison service to compare a library’s journal or book holdings to the Portico archive. Search titles and ISSNs by keyword: Show: E-Books All0-9ABCDEFGHIJKLMNOPQRSTUVWXYZ Titles start with H (1) Information Hidden Depths: The Origins of Human Connection Author/Editor: Penny Spikins