APA (7e ed.) Bronvermelding

Helfert, E. A. (1967). Techniques of financial analysis (Rev. ed.). R.D. Irwin.

Chicago (17e ed.) Bronvermelding

Helfert, Erich A. Techniques of Financial Analysis. Rev. ed. Homewood, Ill.: R.D. Irwin, 1967.

MLA (8e ed.) Bronvermelding

Helfert, Erich A. Techniques of Financial Analysis. Rev. ed. R.D. Irwin, 1967.