Shiva Purana
न शक्यमन्तरं तेषां वक्तुं वर्षशतैरपि ॥ पूर्णे शतसहस्रे तु कल्पो निःशेष उच्यते ॥ ७३ ॥
It is difficult to explain Manvantara even in hundreds of years. The Kalpa that follows a hundred thousand Kalpas is named Niśśeṣa.
english translation
na zakyamantaraM teSAM vaktuM varSazatairapi ॥ pUrNe zatasahasre tu kalpo niHzeSa ucyate ॥ 73 ॥
hk transliteration by Sanscript