" 
 :Thanks for pointing this out, and sorry for missing it. 
 :*Link fixed. 
 :*Added. 
 :*The Korsvoll Line opened on 4 May 1924, four days after the creation of Oslo Sporveier, so it is included under 'all'. 
 :*All companies which were eventually bought by OS, but were for a long time private, are listed as such, with Ekebergbanen no exception. All the companies were eventually bought by the municipality at some time. 
 :  "