Stájer Géza; Csende Ferenc; Bernáth Gábor; Sohár Pál: Preparation and steric structure of tricyclic and tetracyclic saturated or partially saturated 1,3-heterocycles containing a saturated isoindolone moiety. HETEROCYCLES, 37 (2). pp. 883-890. ISSN 0385-5414 (1994)