5. For previous correspondence concerning oil concessions, see Foreign Relations, 1919, vol. i, pp. 865 ff.
- Cancelation of the Tinoco concessions by the Costa Rican Congress—Formal protest by Great Britain on behalf of the Amory concession (Documents 877-885)
- Efforts by the Costa Rican Congress to cancel the Pinto–Greulich concession—Apparent conflict between the terms of the concession and the rights of other American enterprises (Documents 886-895)