Transactions of the American Mathematical Society (Trans. Amer. Math. Soc.) (19970101), 349, no.~10, 3893-3910. ISSN: 0002-9947 (print).eISSN: 1088-6850.
Transactions of the American Mathematical Society (Trans. Amer. Math. Soc.) (19950101), 347, no.~12, 4687-4728. ISSN: 0002-9947 (print).eISSN: 1088-6850.