Ren YH, Qin XQ, Guan CX, Luo ZQ, Zhang CQ, Sun XH. [The temporal and spatial distribution of vasoactive intestinal peptide and its receptor in the development of airway hyperresponsiveness]. Zhonghua Jie He He Hu Xi Za Zhi. 2004 Apr;27(4):224–8. PMID: 15144609.