Shiva Purana
नासिकापुटमंगुल्या पीड्यैकमपरेण तु ॥ औदरं रेचयेद्वायुं तथायं रेचकः स्मृतः ॥ २२ ॥
One of the nostrils is pressed with the finger and the air from the belly is let out through the other. This is Recaka (Exhaling).
english translation
nAsikApuTamaMgulyA pIDyaikamapareNa tu ॥ audaraM recayedvAyuM tathAyaM recakaH smRtaH ॥ 22 ॥
hk transliteration by Sanscript