Most journals recommend that in referencing an electronic source one first make a printed copy of the document for one's own records. The text of the Guide will print out at about 30 pages. Beyond that please feel free to copy and paste the following citation. If you are writing *.html, feel free to copy the table code template for use with the "References Cited" section of your electronic publication.
Stelle, Lenville J. and Thomas P. Duggan
An Archaeological Guide to Chert Types of East-Central Illinois. Center For Social Research, Parkland College. http://virtual.parkland.edu//lstelle1/len/biface_guide/chert/documents/chert_types.html