References
- Strang G. Linear algebra and its applications. 3rd ed. Orlando (FL): Saunders: Harcourt Brace & Company; 1988. ISBN 0-15-551005-3.
- Råde L, Westergren B. Mathematics handbook for science and engineering. 3rd ed. Lund: Studentlitteratur; 1995. ISBN 91-44-25053-3.