From: Delareysfontein
This Prisoner of War record for Marthinus Stijn Greyling was transcribed record from various documents held at the National Archives, South Africa, including arrest and shipping information from newspaper sources like De Zuid-Afrikaan.
https://www.gendatabase.com/boer-war-prisoner-record.php?q=19615&r=Marthinus Stijn&s=Greyling&ref=
This set of Prisoner of War documents can be accessed online via the FamilySearch.org project by Clicking Here.