It's not an on-line guide, it's an e-book by Google Books. There are thousands of them. Here's the link to this one - Click Here This one was published in 1900. Th enice thing about these e-books is that you can create your own on-line library with them. You need to do some exploring
Did you use the enlarging tool? (you can enlarg it at least three times) When you blow it up it becomes an obvious fraction with the denominator below the base line of the rest of the text (a 1 would have ended at the same base line as the D) and you can compare it to the fractions of the denominations of the other tokens
