อักษรกอธิคใดมีต้นกำเนิดมาจาก /ษธ/; /ข/?
Which Gothic Letter has Proto-Germanic origin of /ɸ/; /b/?
df = pd.DataFrame(columns=['gothic_letter', 'proto_germanic_origin'])
df[df['proto_germanic_origin'] == '/ɸ/; /b/']['gothic_letter']