Literature Reference: While 'Yikang' has no direct source, 'Yi' can be found in 'The Book of Songs·Xiaoya·Deer Call' 'I have honored guests, playing the zither and blowing the sheng.' 'Kang' appears in 'The Book of Documents·Hongfan' 'Five Blessings: the first is longevity, the second is wealth, the third is health and peace, the fourth is love for virtue, and the fifth is a good end.'