This pattern is from the book Blueprint Crochet which is available in print and eBook form. It is also available as a single pattern download from the Interweave Store.

Yarn: DK-weight (#3 Light)
Shown: Swirl DK by Lorna’s Laces (85% merino wool, 15% silk; 150 yd 137.5 m/ 1.75 oz 50g): poppy, 10(11, 14, 16) hanks.
Hooks: G/6 (4.25mm) and H/8 (5.0mm) or hooks needed to obtain gauge.
Notions: Tapestry needle; sewing needle and thread.
Optional: 4” (10cm) of ½“ (1.3cm) wide grosgrain ribbon; 1 hook and eye closure.
Gauge: 3½ x 3½” (9 x 9 cm) = Granny Square with smaller hook
37/8 x 37/8” (10 x 10 cm) = Granny Square with larger hook
Size: Small, (Medium, Large, X-Large) fits 30 (33, 40, 44)“ (76.5 84, 102, 112 cm)
bust circumerence and 15 (16½, 20, 22)” (38.5 42, 51, 56 cm) upper arm circumference.
Sweater is shown in a Medium.