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

Available for University of the Philippines Diliman via IEEE Xplore. Click here to access
Also available remotely for University of the Philippines Diliman via IEEE Xplore. Click here to access thru EZproxy

Schaum's outline of precalculus gan Safier, Fred

Available for University of the Philippines Diliman via McGraw-Hill Access Engineering. Click here to access
Also available remotely for University of the Philippines Diliman via McGraw-Hill Access Engineering. Click here to access thru EZproxy

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

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

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

Available for University of the Philippines Diliman via McGraw-Hill Access Engineering. Click here to access
Also available remotely for University of the Philippines Diliman via McGraw-Hill Access Engineering. Click here to access thru EZproxy

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

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

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

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

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