Brewington, A. (1937). Direct-method materials for Gregg shorthand: Teacher's manual. The Gregg Pub. Co..
Lua i Stíl Chicago (17ú heag.)Brewington, Ann. Direct-method Materials for Gregg Shorthand: Teacher's Manual. New York : Chicago [etc.]: The Gregg Pub. Co., 1937.
Lua MLA (8ú heag.)Brewington, Ann. Direct-method Materials for Gregg Shorthand: Teacher's Manual. The Gregg Pub. Co., 1937.
Rabhadh: Seans nach mbeach na luanna seo go hiomlán cruinn i ngach uile chás.