For All the Saints
- Biographical sketch of St. Olaf, King of Norway. Gives as variants on the saint's name: Olave, Ola, Olao, Tola, and Tooley.
- http://www.saintpatrickdc.org/ss/0729.htm#tool

Catholic Online
- Biographical sketch of St. Olaf, patron saint of Norway. His feast day is 29 July.
- http://www.catholic.org/saints/saint.php?saint_id=132

Catholic Encyclopedia
- St. Olaf Haraldson, martyr and King of Norway, d. 1030.
- http://www.newadvent.org/cathen/11234a.htm

Snorri Sturlason: Heimskringla
- The Saga of Olaf Haraldson. In eight parts, by an important chronicler of the Viking age.
- http://sunsite.berkeley.edu/OMACL/Heimskringla/haraldson1.html

Patron Saints Index
- Profile of St. Olaf II, also known as St. Olaf Haraldson, Olaf Haraldsson, Olav II, Olav the Thick, or Olaf the Fat.
- http://www.catholic-forum.com/saints/sainto07.htm