TY  - RPRT
TI  - Crossover designs versus parallel studies in infertility research.
AU  - E R te Velde
AU  - B J Cohlen
AU  - C W Looman
AU  - J D Habbema
PY  - 1998
DO  - 10.1016/s0015-0282(97)00491-3
UR  - https://pubmed.ncbi.nlm.nih.gov/9496358/
ID  - 9496358
ER  -