B: Course in Pharmaceutical Arithmetic: Including Weights and Measures (1903)

By Julius William Sturmer 

https://books.google.com/books?id=oY80AQAAMAAJ&pg=PA60&dq=pharmaceutical+calculations&hl=en&sa=X&ved=0ahUKEwiunvqUycbVAhVL4iYKHQ82BH4Q6AEINjAD#v=onepage&q=pharmaceutical%20calculations&f=false

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