Digital Libraries at the Crossroads of Digital Information for the FutureThis book constitutes the refereed proceedings of the 21st International Conference on Asia Pacific Digital Libraries, ICADL 2019, held in Kuala Lumpur, Malaysia, in November 2019. The 13 full, 13 short, and 5 poster papers presented in this volume were carefully reviewed and selected from 54 submissions. The papers were organized in topical sections named: text classification; altmetrics; scholarly data analysis and recommendation; metadata and