Natyashastra
उत्तरस्यां दिशि तथा धनदं संनिविएशयेत् । नाट्यस्य मातॄश्च तथा यक्षानथ सगुह्यकान् ॥ ३०॥
In the northern direction, Kubera should be stationed, along with the Mothers of Nāṭya, the Yakṣas, and the Guhyakas.
english translation
uttarasyAM dizi tathA dhanadaM saMniviezayet । nATyasya mAtRRzca tathA yakSAnatha saguhyakAn ॥ 30॥
hk transliteration by Sanscript