- Drummond castle & gardens: www.drummondcastlegardens.co.uk
- Thesis Drummond estate management: Openaccess Leiden Universteit
- Muthill Parish records: Muthill Parish records
Literatuur
- Lord Willoughby’s Railway, the Edenham Branch, Pearson & Ruddock (1986)(re. Grimsthorpe estate)
- Drummond castle & gardens: www.drummondcastlegardens.co.uk
- Thesis Drummond estate management: Openaccess Leiden Universteit
- Muthill Parish records: Muthill Parish records
Literatuur
- Lord Willoughby’s Railway, the Edenham Branch, Pearson & Ruddock (1986)(re. Grimsthorpe estate)
English (UK) 
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