Shiva Purana
यद्वा मूर्धादिपञ्चांगं न्यासमेव समाचरेत् ॥ तथा षडंगन्यासं च भूतशुद्ध्यादिकं विना ॥ १९ ॥
Or he need perform only the Nyāsa of the five limbs beginning with the head. Similarly the Nyāsa of six limbs without the rites of purification etc. of the Bhūtas shall be performed.
english translation
yadvA mUrdhAdipaJcAMgaM nyAsameva samAcaret ॥ tathA SaDaMganyAsaM ca bhUtazuddhyAdikaM vinA ॥ 19 ॥
hk transliteration by Sanscript