Gray Adam, A Scots agricultural glossary, Dumfries, Dumfries and Galloway Family History Society, 1997

Graham William, The Scots word book, Edinburgh, Ramsay Head Press, 1980
Primarily an English-Scots, Scots-English dictionary with brief sections on idiom, grammar, spelling and pronounciation.

Jamieson John, An etymological dictionary of the Scottish language (3 volumes), Paisley, Alexander Gardner, 1879
Despite it's age, it still stands as a standard work on the origin of Scots words.

Jamieson John, Jamieson's dictionary of the Scottish language, Paisley, Alexander Gaedner, 1910
Somewhat dated one volume dictionary.

The compact Scottish national dictionary : containing all the Scottish words, Aberdeen, Aberdeen University Press
Good for day to day adult use.

Scots school dictionary : Scots-English, English-Scots, ed Iseabail MacLeod, Edinburgh, Polygon, 1999