APA-referens (7:e uppl.)

Philippines. (1921). Internal Revenue Laws of The Philippine Islands In Force and Effect July 1, 1921. WEL Collection.

Chicago-referens (17:e uppl.)

Philippines. Internal Revenue Laws of The Philippine Islands In Force and Effect July 1, 1921. [S.l.]: WEL Collection, 1921.

MLA-referens (9:e uppl.)

Philippines. Internal Revenue Laws of The Philippine Islands In Force and Effect July 1, 1921. WEL Collection, 1921.