Comprehensive index to the Flora of Guatemala / Terua P. Williams.

v.24:pt.13(1977)

Tropical American plants, VIII / Louis O. Williams.

v.31:no.10(1967)

Tropical American plants, III / Louis O. Williams.

v.29:no.7(1962)

Flora of Guatemala / Paul C. Standley, Louis O. Williams, Dorothy Nash Gibson.

v.24:pt.10:no.3-4(1974)

Flora of Guatemala / Paul C. Standley and Louis O. Williams.

v.24:pt.8:no.4(1969)

Flora of Guatemala / Paul C. Standley and Louis O. Williams.

v.24:pt.8:no.1-2(1966)

Notes on the flora of Costa Rica, I / [by] William C. Burger.

v.31:no.11(1968)

Flora Costaricensis / William Burger, editor.

n.s. no.36(1995)

Flora Costaricensis / William Burger, editor.

n.s. no.33(1993)

Hoffmannias from Mexico and Central America [by] Louis O. Williams.

v.36:no.6(1973)

Tropical American plants, XVII / Louis O. Williams.

v.36:no.10(1975)

Bignoniaceae of tropical North America [by] Louis O. Williams.

v.36:no.4(1973)

Flora Costaricensis / William Burger, editor.

n.s. no.23(1990)

Flora Costaricensis. William Burger, editor. Family #40, Casuarinaceae, Family #41, PIperaceae [by] William Burger.

v.35(1971)

Flora Costaricensis / William Burger, editor.

n.s. no.13(1983)