Published in Gardens' Bulletin, Singapore, in 1971, in volume 25, issue 3, pages 335-353

Published in Gardens' Bulletin, Singapore, in 1971, in volume 25, issue 3, pages 355-381

Published in Gardens' Bulletin, Singapore, in 1971, in volume 25, issue 3, pages 383-384

Published in Gardens' Bulletin, Singapore, in 1971, in volume 25, issue 3, pages 385