Electronic reference works published by Springer cannot be accessed directly through EDUCAT, the TC lists of e-journals and databases, or CLIO.
They are included in the SpringerLink database to which Columbia subscribes.
They are best searched by Series Title, ie. Springer International Handbooks of Education.
Other series titles that may be of interest to you:
International Handbook of Comparative Education
International Handbook of Research on Teachers and Teaching
International Handbook of Information Technology in Primary and Secondary Education
International Handbook of Urban Education
International Handbook of Higher Education
International Handbook of School Effectiveness and Improvement
International Handbook of Research in Arts Education
International Handbook of English Language Teaching
International Handbook of Educational Policy
International Handbook of Self-Study of Teaching and Teacher Education Practices