k K. BONIA and J. GOSWAMI, “Serum 17β- oestradiol, progesterone and cortisol level during biological stress period of normal and sub-oestrous cycles of crossbred cattle of Asom”, Indian J of Anim Sci, vol. 81, no. 7, Jul. 2011, doi: 10.56093/ijans.v81i7.7716.