The doctrine of triangles a history of modern trigonometry door Van Brummelen, Glen

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Schaum's outline of precalculus door Safier, Fred

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Three-way journal writing effects on students' problem-solving and self-regulation skills in trigonometry door Lugtu, Ivy C.

Precalculus functions and graphs door Swokowski, Earl William 1926-, Cole, Jeffery A. 1955-

Schaum's outline of trigonometry door Moyer, Robert, Ayres, Frank 1901-1994

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The fractional trigonometry with applications to fractional differential equations and science door Lorenzo, Carl F., Hartley, Tom T.

A basic approach to precalculus trigonometry preparing to succeed in calculus door Kim, Young H., Kim, Youngsoo, Tameru, Ana, Yan, Wen

Plane & spherical trigonomerty a tetrahedron approach door Mamhot, Millard R., Endam, Joemar C., Mamhot, Alice A., Banagua, Emelyn C., Bantug, Jenette S.

Worktext in college trigonometry door Domingo, Alleli C., Dimasuay, Lynie B., Lawas, Vernel M., Lubag, Sharon P., Almonte, Velimor D.

Plane & spherical trigonometry a tetrahedron approach door Mamhot, Millard R., Endam, Joemar C., Mamhot, Alice A., Banagua, Emelyn C., Bantug, Jenette S.