Most of those farms will be in the same parish or another nearby. The PDF file online for Langåker is only one of many the local history/genealogy group for that island has extracted and put online for anyone to use.
You can also use any of the other farms that have been completed and put online.

Go to the homepage for the group "Slektsforum Karmøy" at
http://www.slektsforumkarmoy.no/english/

From the left hand column choosing "County Books" will take you to the names of the farms and those for which compiled data are available online will be linked. I notice today they have continued to make great progress in adding additional information online.