Apple II Language Reference Manual
This manual describes the Apple FORTRAN programming language for the Apple II and Apple II-plus computers. Apple FORTRAN conforms to the American national Standard FORTRAN subset, also known as ANSI subset FORTRAN 77.
Apple Product #A2D0032 (030-0118-00)
This book originally came with the FORTRAN language package. If I can find the disks, this manual will be included in the package.