Sources
Verify citations and extract evidence
Firm Resources and Sustained Competitive Advantage
Jay B. Barney (1991)
“A firm is said to have a sustained competitive advantage when it is implementing a value creating strategy not simultaneously being implemented by any current or potential competitors and when these other firms are unable to duplicate the benefits of this strategy.”
“Resource heterogeneity and immobility are necessary conditions for sustained competitive advantage.”
The Five Competitive Forces That Shape Strategy
Michael E. Porter (2008)
“Understanding the competitive forces, and their underlying causes, reveals the roots of an industry's current profitability while providing a framework for anticipating and influencing competition over time.”
Contemporary Strategy Analysis
Robert M. Grant (2021)
“Industry attractiveness varies significantly across sectors, and structural analysis helps explain why some industries are consistently more profitable than others.”
Strategies for Diversification
H. Igor Ansoff (1957)
“[TO BE VERIFIED]”
The Resource-Based View: A Review and Assessment
Kraaijenbrink, Spender & Groen (2010)
No evidence extracted yet
Based on your outline, Section 5 (Strategic Options) references Ansoff but lacks a second supporting source. I'd suggest looking for a recent meta-analysis of the Ansoff matrix in technology-driven industries.
Section 4 discusses VRIO but currently only cites Barney (1991). Consider adding Kraaijenbrink et al. (2010) for a critical review of the RBV — it would strengthen the counter-argument.