1. On the number of solutions of nonlinear equations in ordered Banach spaces;Amann;J. Functional Analysis,1972
2. Non-compact positive operators;Edmunds,1972
3. Ordered Linear Spaces;Jameson,1970
4. Positive Solutions of Operator Equations;Krasnosel'skii,1964
5. Linear operators leaving invariant a cone in a Banach space;Krein;Amer. Math. Soc. Transl.,1962