Hart, H.L.A.
The concept of law
Clarendon Press, 1979
 Buku Teks SO
Hart, H.L.A.
The concept of law
United Kingdom Oxford University Press, 2012
 Buku Teks
Lupis, Ingrid Detter de
The concept of international law
Norsteds Forlag, 1987
 Buku Teks
Helminen, Marjaana
The international tax law concept of dividend
Wolters Kluwer Law & Business, 2010
 Buku Referensi
Helminen, Marjaana
The international tax law concept of dividend
Wolters Kluwer, 2010
 Buku Teks