SPECIFICATION OF SPL SPACE PROGRAMMING LANGUAGE,
Levi J. Carey, Kroger,Al E., Shaw,Christopher J. · Defense Technical Information Center (DTIC) · 1967
The document contains a complete specification of the Space Programming Language (SPL) in Backus-Naur form. A description of basic SPL and extensions is given. SPL is a space application language with a large array of capabilities. It is further an extendable language with punctuation rules and vocabulary designed for ease of learning and programming. (Author)