HSU, H. W. C., ARANAS, D. R., ALEJANDRO, G. J. D., & LIEDE-SCHUMANN, S. (2020). A new species of <em>Argostemma </em>(Rubiaceae)<em> </em>with free stamens in star-shaped corolla from the Philippines. Phytotaxa, 437(2), 113–117. https://doi.org/10.11646/phytotaxa.437.2.7