Labradorite from
USA | |
| Schooner, Richard. (1958): The Mineralogy of the Portland-East Hampton-Middletown-Haddam Area in Connecticut (With a few notes on Glastonbury and Marlborough). |
| Foye, Wilbur G. (1926) The occurrence of thulite at Haddam, Connecticut. American Mineralogist, 11 (8) 210-212 |
| Betts, John (n.d.) John Betts website listing. |