Gough, K. John
Addison-Wesley, 1988
Buku Teks
edited by Adam Ledgeway and Ian Roberts
Cambridge University Press, 2017
Buku Teks
koster, Jan
Foris Publications Dordrecht, 1978
Buku Teks
Ackema, Peter
LED , 1995
Buku Teks
Dal, Ingerid
Tubingen Max Niemeyer 1952
Buku Teks