The 1900 Norwegian census would be the most likely resource to check first.
In the 1900 census there are at least 7 young boys born between 1891 and 1895 with 'Ant' in their given name and last names starting with 'Mag' -- none of those are in Stavanger at that time or listed with a birthplace of Stavanger.
Peder found a matching Anton with birthplace listed as Stavanger in the 1910 census though. It is most likely that he also appears in the 1900 but with wrong birthplace listed.
So the two that would seem to match your inquiry would be -
1900 census -http://www.rhd.uit.no/folketellinger/ftliste_e.aspx?ft=1900&...
The same family in the 1910 census - http://www.rhd.uit.no/folketellinger/ftliste_e.aspx?ft=1910&...http://homepages.rootsweb.ancestry.com/~norway/census_abbrev...http://home.online.no/~otjoerge/files/word.htm
To research in detail for original records of vital events in his life and that of his ancestors you will want to use the Norwegian church records.
The Digitalarkivet web site has been adding scanned images of the original Norwegian parish church records for anyone with Internet access since November 2005.
The Digitalarkivet web site - http://digitalarkivet.uib.no/cgi-win/WebFront.exe?slag=vis&a...
An English option is available by clicking on that word from either the left hand column or the blue link bar along the bottom of the homepage.
The scanned images are available from the homepage link "Skanna kyrkjebøker" [Norwegian version]/"Digitised parish records" [English version] which is listed along the left hand column and from the blue banner of links along the top section of the homepage.
Clicking on "Skanna kyrkjebøker" [Norwegian version]/"Digitised parish records" [English version] will bring up another screen and listing to choose from. Choose "Lesa skanna kyrkjebøker" [Norwegian version]/"Read the digitised parish records" [English version].
After you've clicked on that link and a new main page has presented on the screen be sure and read the instructions that are available from the Digitalarkivet for navigating the scanned records. The instructions are available in Bokmål (official Norwegian), Nyorsk (Norwegian), Davvisámegiella (Saami), and English.
Recommended basic reading are the "Startsiden" [Norwegian version]/"Main page" [English version], "Brukerveiledning" [Norwegian version]/"User's guide" [English version] and "Om tjenesten" [Norwegian version]/"About this service" [English version].
Good information about translating the formats of Norwegian parish church records during various time periods, many of the basic terms used and understanding how to use the information should be studied at this web site -http://homepages.rootsweb.com/~norway/na20.html
For the protection of privacy, there are limits for how recent church records can be published:
- Birth and baptism records up to and including 1929
- Confirmation records up to and including 1934
- Marriage and banns records - no limits
- Civil marriage up to and including 1950
- Death, burial and stillbirth records up to and including 1930
- Migration records - no limits
- Joins and leavings of the State Church up to and including 1950
- Records about dissenters up to and including 1950
If you cross these limits while browsing a register or a list, you will not see the digitised image, but a message informing you that the image cannot be displayed.