The whetstone of witte, whiche is the seconde parte of Arithmetike: containyng thextraction of Rootes: The Coßike practise, with the rule of Equation: and the woorkes of Surde Nombers

The 1557 published book The Whetstone of Witte by Robert Recorde is  one of the key texts in the history of mathematics. The Whetstone of Witte was the book that introduced the equals sign in its modern form (as well as the first book in English to use the plus and minus signs).    
    
    See page 238 of the (pdf) file.

Even the notion binomial first appears as a noun in English  in 1557 in The Whetstone of Witte book of Robert Recorde as: "The nombers that be compound with + be called Bimedialles... If their partes be of 2 denominations, then thei named Binomialles properly. Howbeit many vse to call Binomialles all compounde nombers that have +".

@book{recorde_whetstone_1557,
    title = {The whetstone of witte, whiche is the seconde parte of {Arithmetike}: containyng thextraction of {Rootes}: {The} {Coßike} practise, with the rule of {Equation}: and the woorkes of {Surde} {Nombers}},
    copyright = {},
    url = {},
    abstract = {
One of the key texts in the history of mathematics. The Whetstone of Witte was published in 1557, and was the book that introduced the equals sign in its modern form (as well as the first book in English to use the plus and minus signs).    
    
    See page 238 of the (pdf) file.

Even the notion binomial first appears as a noun in English  in 1557 in The Whetstone of Witte by Robert Recorde: "The nombers that be compound with + be called Bimedialles... If their partes be of 2 denominations, then thei named Binomialles properly. Howbeit many vse to call Binomialles all compounde nombers that have +".

},
    language = {English},
    place = {London},
    publisher = {Jhon Kyngstone},
    author = {Recorde, Robert},
    year = {1557},
    keywords = {Arithmetic, Algebra, Mathematics}
, note={
\href{https://archive.org/details/TheWhetstoneOfWitte}{archive.org, San Francisco, CA 94118, USA}}
}

see also: archive.org, San Francisco, CA 94118, USA