Astanga Hrudaya
मुष्कवङ्क्षणयोर्मध्ये विटपं षण्ढताकरम्। इति सक्थ्नोस्तथा बाह्णोर्मणिबन्धोऽत्र गुल्फवत्॥८॥
In between the scrotum and groin is vitapa, its injury causes impotence. Marmas of the arms are similar to those of the thighs; in the arms, just like the gulpha, it is manibandha (called manibandha or wrist marma instead of gulpha).
english translation
muSkavaGkSaNayormadhye viTapaM SaNDhatAkaram। iti sakthnostathA bAhNormaNibandho'tra gulphavat॥8॥
hk transliteration by Sanscript