Active immunization with GnRH-tandem-dimer peptide in young male rats reduces serum reproductive hormone concentrations, testicular development and spermatogenesis oleh Xing-Fa Han, Jun-Li Li, Yu-Qin Zhou, Xiao-Hua Ren, Gong-Cheng Liu, Xiao-Han Cao, Xiao-Gang Du, Xian-Yin Zeng