@misc
{TN_libero_mab2,
author = {
Heck, Ronald H.
},
title = {
Principals' Instructional Leadership and School Performance: Implications for Policy Development
},
publisher = {SAGE Publications},
isbn = {0162-3737},
keywords = {
Education
},
year = {1992},
url = {
http://slubdd.de/katalog?TN_libero_mab2
}
}