@book{Hufnagel2010, author = {Hufnagel, W.}, title = {Managementsysteme, LE 1}, address = {Hagen}, year = {2010}, language = {mul} } @book{HufnagelKuehn2009, author = {Hufnagel, W. and K{\"u}hn, R.}, title = {Betriebliches Rechnungswesen, Externes Rechnungswesen, LE 1-4}, address = {Hagen}, year = {2009}, language = {mul} } @book{HufnagelRueth2010, author = {Hufnagel, W. and R{\"u}th, D.}, title = {Internes Rechnungswesen, LE 1-5}, address = {Hagen}, year = {2010}, language = {mul} } @book{Hufnagel2011, author = {Hufnagel, W.}, title = {Management unterst{\"u}tztes Controlling, LE1 - LE 4}, address = {M{\"u}nster}, year = {2011}, language = {mul} }