Spanning trees with at most 4 leaves in K1, 5-free graphs. - Yuan Chen; Pham Hoang Ha; Dang Dinh Hanh (Discret. Math., 2019)

A note on the independence number, connectivity and k-ended tree. - Pham Hoang Ha (Discret. Appl. Math., 2021)

The Conflict-Free Vertex-Connection Number and Degree Conditions of Graphs. - Trung Duy Doan; Pham Hoang Ha; Ingo Schiermeyer (Graphs Comb., 2022)

The conflict-free connection number and the minimum degree-sum of graphs. - Trung Duy Doan; Thi Thanh Chau Do; Pham Hoang Ha; Ngoc Diep Pham; Ingo Schiermeyer (Appl. Math. Comput., 2024)

Spanning trees of K1,4-free graphs whose reducible stems have few leaves. - Pham Hoang Ha; Le Dinh Nam; Ngoc Diep Pham (Period. Math. Hung., 2024)