Manasara 7.39

7.39

catuṣkaiśca ṣaḍādhikyaṃ triṃśatsaṃyuktameva ca
ṣaṭkadvādaśasaṃyuktaṃ karṇe śūlaṃ catuṣṭayam

and with thirty-six squares,
with six and twelve joined, there are four corner spikes;