Srimad-Bhagavatam: Canto 2 - Chapter 1 - Verse 42

Sanskrit:

भूर्लोक: कल्पित: पद्‍भ्यां भुवर्लोकोऽस्य नाभित: ।स्वर्लोक: कल्पितो मूर्ध्ना इति वा लोककल्पना ॥ ४२ ॥

ITRANS:

bhūrlokaḥ kalpitaḥ padbhyāṁbhuvarloko ’sya nābhitaḥsvarlokaḥ kalpito mūrdhnāiti vā loka-kalpanā

Translation:

Others may divide the whole planetary system into three divisions, namely the lower planetary systems on the legs [up to the earth], the middle planetary systems on the navel, and the upper planetary systems [Svarloka] from the chest to the head of the Supreme Personality.

Purport:

The three divisions of the complete planetary systems are here mentioned; fourteen are imagined by others, and that is also explained.