On the existence of the essential spectrum for a class of differential expressions having normal maximal extensions

ग्रंथसूची विवरण
मुख्य लेखक:	Castillo, Maritina T.
स्वरूप:	थीसिस
भाषा:	English
प्रकाशित:	1999.
विषय:	Spectral theory (Mathematics). Differential operators.