Brown, Alexander Crum: "On the division of a parallelepiped into tetrahedra without making new corners", [A fuller investigation will be found in the Transactions of the Royal Society of Edinburgh, Vol. XXXVII, pp. 711-719 (1895)]
Jackson, Frank Hilton: "The solutions to the differential equations {cos (
( d/dx) )} y = 
(x), {sin ( ( d/dx) )} y = (x)", {Title in minutes: "On two differential equations"}