1
od Beatty, Richard H., 1939-
Wydane 2002
Full text available from Career & Technical Education Database
Elektroniczne E-book
2
od Kennedy, Joyce Lain.
Wydane 2009
Full text available from Career & Technical Education Database
Elektroniczne E-book
3
od Kennedy, Joyce Lain.
Wydane 2007
Full text available from Career & Technical Education Database
Elektroniczne E-book