Shiva Purana
दक्षिणे स्थापयित्वा तु बिल्वपत्रैः समर्चयेत् ॥ अगुरुं दक्षिणे पार्श्वे पश्चिमे तु मनःशिलाम् ॥ ११ ॥
Placing the deity on the right side, one should worship the deity with bilva leaves. Aguru on the southern side and Manasshila on the west.
english translation
dakSiNe sthApayitvA tu bilvapatraiH samarcayet ॥ aguruM dakSiNe pArzve pazcime tu manaHzilAm ॥ 11 ॥
hk transliteration by Sanscript