@article {heefferinterpretation,
	title = {On the interpretation of early Italian bartering problems},
	year = {Submitted},
	author = {Heeffer, Albrecht}
}
@article {420317,
	title = {An introduction to wasan, native {J}apanese mathematics},
	journal = {History and Pedagogy of Mathematics},
	volume = {68},
	year = {2008},
	pages = {20{\textendash}24},
	issn = {N/A},
	url = {http://dx.doi.org/1854/11413},
	author = {Heeffer, Albrecht}
}
