A Comprehensive Meta-analysis of Handwriting Instruction - Santangelo, T; Graham, S (2016)
meta-analysis; evidence grade C

Is handwriting causally related to learning to write? Treatment of handwriting problems in beginning writers. - Graham, S; Harris, KR; Fink, B (2000)
rct; evidence grade C

Treatment of handwriting problems in beginning writers: Transfer from handwriting to composition. - Berninger, VW; Vaughan, KB; Abbott, RD; Abbott, SP; Rogan, LW; Brooks, A; Reed, E; Graham, S (1997)
rct; evidence grade C

Writing instruction improves students’ writing skills differentially depending on focal instruction and children: A meta-analysis for primary grade students - Kim, YSG; Yang, D; Reyes, M; Connor, C (2021)
meta-analysis; evidence grade C

A Meta-Analysis of Writing Instruction for Students in the Elementary Grades. - Graham, S; McKeown, D; Kiuhara, S; Harris, KR (2012)
meta-analysis; evidence grade C

The impact of digital devices vs. Pen(cil) and paper on primary school students' writing skills – A research review - Wollscheid, S; Sjaastad, J; Tømte, C (2016)
review; evidence grade C

The roles of handwriting and keyboarding in writing: a meta-analytic review - Feng, L; Lindner, A; Ji, XR; Joshi, RM (2019)
meta-analysis; evidence grade D

Genetic and environmental influences on writing and their relations to language and reading - Olson, RK; Hulslander, J; Christopher, M; Keenan, JM; Wadsworth, SJ; Willcutt, EG; Pennington, BF; DeFries, JC (2013)
twin-adoption; evidence grade B