@article{56a9a77f1070425ba057ce0cb0bc2d43,
title = "The ultrastructure and botanical affinity of end-Permian spore tetrads",
keywords = "Permian, tetrads, spores, ultrastructure, lycopsids, HETEROSPOROUS LYCOPHYTES, MEGASPORE DEVELOPMENT, SELAGINELLA, LYCOPSIDA, MICROSPORES, PLEUROMEIA, ORIGIN, NOV",
author = "Looy, \{C V\} and Collinson, \{M E\} and Cittert, \{J H A V\} and H Visscher and Brain, \{A P R\}",
year = "2005",
month = sep,
language = "English",
volume = "166",
pages = "875--887",
journal = "International Journal of Plant Sciences",
issn = "1058-5893",
publisher = "University of Chicago Press",
number = "5",
}