BibTex format
@article{JOHNSON:1993:10.1093/oxfordjournals.humrep.a138043,
author = {JOHNSON, MR and RIDDLE, AF and GRUDZINSKAS, JG and SHARMA, V and CAMPBELL, S and COLLINS, WP and LIGHTMAN, SL and MASON, B and NICOLAIDES, KH},
doi = {10.1093/oxfordjournals.humrep.a138043},
journal = {HUMAN REPRODUCTION},
pages = {316--322},
title = {ENDOCRINOLOGY OF INVITRO FERTILIZATION PREGNANCIES DURING THE 1ST TRIMESTER},
url = {http://dx.doi.org/10.1093/oxfordjournals.humrep.a138043},
volume = {8},
year = {1993}
}