Use the article number followed by a period.
Based on Author Guidelines, Reproduction, https://rep.bioscientifica.com/page/437#Manuscript%20formatting
Cite references in the text using the authors' names and publication year.
(Last name Year)
(Last name & Last name Year)
(Donnez & Dolmans 2015)
(First author's last name et al. date)
(Ginther et al. 2009)
(Provoost et al. 2014, Donnez & Dolmans 2015, Vander Ven et al. 2016)
Used in this sentence:
Recently, OTC has been classified as an innovative treatment according to the criteria of the American Society for Reproductive Medicine (ASRM), European Society of Human Reproduction and Embryology (ESHRE) and the special interests groups ‘Ethics and Law’ and ‘Safety and Quality in Assisted Reproductive Technology’ and no longer been considered as an experimental technique (Provoost et al. 2014, Donnez & Dolmans 2015, Van der Ven et al. 2016).
All examples are from the following article:
Gastal GDA, Alves BG, Alves KA, Souza MEM, Vieira AD, Varela AS, Figueiredo JR , Feugang JM, Lucia T Jr., Gastal EL 2017 Ovarian fragment sizes affect viability and morphology of preantral follicles during storage at 4°C. Reproduction 153 577-587. (doi: 10.1530/REP-16-0621)