| title | ISBN-13 (ISBN-10) | year of publication |
|---|---|---|
| On the Origin of the Acid Volcanic Rocks Around Lake Toba, North Sumatra | 978-0-7204-8405-2 (0-7204-8405-7) | 1947 |
| Radioactivity and Chemistry of Some Indonesian Eruptive Rocks | 978-0-7204-8406-9 (0-7204-8406-5) | 1954 |