Bened, A., Durand, R., Pioch, D., Geneste, P., Declercq, J.-P., Germain, G., Rambaud, J., & Roques, R. (1981). Dipolar Cycloaddition On the Transient Thiophene Sulfone - Isoxazoline and Isoxazolidine Derivatives. The Journal of Organic Chemistry, 46(17), 3502-3505. https://doi.org/10.1021/jo00330a024 (Original work published 1981)