TERRESTRIAL ISOMAGNETIC LINES FOR SOUTH AFRICA FOR THE EPOOH JULY 1, 1903
Published in Transactions of the Royal Society of South Africa, in 1910, in volume 2, issue 1, pages 283-286
Date published:1910
Published in Transactions of the Royal Society of South Africa, in 1910, in volume 2, issue 1, pages 283-286
Date published:1910