Divisions of both Session Laws and Minnesota Statutes may be called chapters, but a reference to Minnesota Statutes will usually be to a section number. For example, chapter 335 of the statutes will be divided into sections, perhaps beginning with 335.01. The proper citation for this would be "Minnesota Statutes, section 335.01" or "Minnesota Statutes 1990, section 335.01."
The numbers at the end of a section represent the history of that particular section. For example, [1959 c 67 s 3; 1963 c 861 s 10; 1974 c 370 s20] means that the section was new in 1959 and was contained in the Laws of Minnesota 1959, chapter 67, section 3. It was amended in Laws 1963, chapter 861, section 10, and amended again in Laws 1974, chapter 370, section 20. If you look up those chapters of those particular Session Laws, you will find what changes were made.