1. On the integral equation 𝜆𝑓(𝑥)=∫₀^{𝑎}𝐾(𝑥-𝑦)𝑓(𝑦)𝑑𝑦;Bellman, Richard;Proc. Amer. Math. Soc.,1952
2. G. F. Carrier, On the asymptotic integration of integral equations, unpublished report to the Los Alamos Scientific Laboratory.
3. \bysame, Integral equation boundary layer problems, 50 Jahre Grenzschichtforschung, Festschrift (for Prandtl), 1954.
4. R. Courant and D. Hilbert, Methoden der mathematischen Physik, vol. 1, Berlin, 1931.
5. On the eigenvalues of certain Hermitian forms;Kac, M.;J. Rational Mech. Anal.,1953