Gaya APA
}, J., M., P., {., E., A. (2008).
Espertise™ A guideline for excellent impressions in theory and practice (2008).
Germany:
3M ESPE.
Gaya MLA
}, John, M, Powers, {, Et, Al.
"Espertise™ A guideline for excellent impressions in theory and practice".
2008
Germany:
3M ESPE,
2008.
Buku Pelajaran.