@article {PCE:PCE2367,
	title = {Characterization of C3{\textendash}C4 intermediate species in the genus Heliotropium L. (Boraginaceae): anatomy, ultrastructure and enzyme activity},
	journal = {Plant, Cell \& Environment},
	volume = {34},
	number = {10},
	year = {2011},
	pages = {1723{\textendash}1736},
	publisher = {Blackwell Publishing Ltd},
	doi = {10.1111/j.1365-3040.2011.02367.x},
	url = {http://dx.doi.org/10.1111/j.1365-3040.2011.02367.x},
	author = {Muhaidat, R. and Sage, T. L. and Frohlich, M. W. and Dengler, N. G. and Sage, R. F.}
}
@article {PCE:PCE1706,
	title = {The functional significance of C3{\textendash}C4 intermediate traits in Heliotropium L. (Boraginaceae): gas exchange perspectives},
	journal = {Plant, Cell \& Environment},
	volume = {30},
	number = {10},
	year = {2007},
	pages = {1337{\textendash}1345},
	publisher = {Blackwell Publishing Ltd},
	doi = {10.1111/j.1365-3040.2007.01706.x},
	url = {http://dx.doi.org/10.1111/j.1365-3040.2007.01706.x},
	author = {Vogan, P. J. and Frohlich, M. W. and Sage, R. F.}
}
@mastersthesis {450,
	title = {Systematics of Heliotropium section Orthostachys in Mexico},
	year = {1978},
	school = {Harvard University},
	address = {Cambridge, Massachusetts},
	author = {Frohlich, M. W.}
}
@inbook {451,
	title = {Heliotropium},
	booktitle = {Flora de Veracruz},
	volume = {18},
	year = {1981},
	month = {1981///},
	pages = {70 - 104},
	publisher = {Instituto Nacional de Investigaciones sobre Recursos Bi{\'o}ticos},
	organization = {Instituto Nacional de Investigaciones sobre Recursos Bi{\'o}ticos},
	address = {Xalapa},
	author = {Frohlich, M. W.},
	editor = {G{\'o}mez-Pompa,A.}
}
