The seminal 1969 paper of W.A. Harris Jr., Y. Sibuya, and L. Weinberg provi
ded new proofs for the Perron-Lettenmeyer theorem, as well as several other
classical results, and has stimulated renewed consideration of families of
regular solutions of certain singular problems. In this paper we give some
further applications of the method developed there and, in addition, exami
ne some connections between the Lettenmeyer theorem and an alternative theo
rem which addresses a problem posed by H.L. Turrittin that dates back to an
1845 example of Briot and Bouquet.