Strunk & White is a guide on writing text in the English language. The guide is contained in a book titled “The Elements of Style”. It was written written by William Strunk Jr. in the 1910s and later expanded by E. B. White in the 1950s.
The guide is relatively short (~80 pages) compared to definitive guides like “Chicago Manual of Style” (~1000 pages), “America Psychological Association (APA Guide)” (~400 pages).
The following are Wikipedia articles of these style guides: